While we don't know anything for sure about the HTC One M9 (other than the fact that it's coming and is probably codenamed Hima), it's going to be a massive deal - will it be the best Android phone of 2015?
Mooted specs include: a QHD display, a Snapdragon 810 processor, 3GB of RAM, a waterproof body and more megapixels in the camera, making the One M9 one of the highest-specification phones on the market.
Updates: A new photo of the phone has appeared, a shot supposedly taken with the camera and a benchmark has given up a number of specs.
Cut to the chase
What is it? HTC's next flagship smartphone
When is it out? Launch event set for March 1
What will it cost? Likely at least £549 / $649 / AU$849
HTC One M9 release date
HTC has sent out invites to an event on March 1 at MWC 2015 in Barcelona, and it's almost certainly going to unveil it's next flagship smartphone here.
The invite reads "utopia in progress" - possibly a hint at the name for the flagship phone, or perhaps it's another new camera mode HTC has developed.
What we do know is we'll be there, reporting live on the event so you get all the latest news as it breaks.
News and rumors
The most recent rumors regarding this new phone seem to make the most sense: the HTC One M9 will have an octa core Qualcomm 810 Snapdragon chipset at the heart, according to recent benchmarks - which saw it score over 20% better results compared to the One M8.
This dovetails with rumours from retired leaker @upleaks, saying the new HTC phone will have 3GB of RAM and an octa-core 64-bit Snapdragon 810 processor, with four cores running at 2.0GHz and four at 1.5GHz, allowing it to switch between them depending on what it's doing, using the slower cores to conserve battery when the extra power isn't needed.
Further rumors have corroborated and smoothed these early specs: from a source speaking to Bloomberg stated that there will be a 20MP snapper on the back and an UltraPixel one on the front (probably 4 UltraPixels but that's not specified).
The 20MP camera theory has been made ever more likely as a picture, apparently snapped by the One M9, has made its way onto the web, detailing a 16:9 20MP photo.
The source goes on to say that the HTC One M9 / Hima will include Dolby 5.1 audio technology.
A rumor from GforGames states the HTC One M9 might have a MediaTek processor rather than a Qualcomm one, but if it does that will likely be a regional version for China and possibly some other markets but not the whole world.
While it's possible that all versions will sport it we'd be surprised, as MediaTek chips tend to be cheaper and less powerful than Qualcomm's. More likely if this is on the cards at all it will be for developing markets.
Unsurprisingly it's rumored to run Android 5.0 Lollipop but that's hardly a surprise - imagine if it launched on KitKat?
In terms of power, it will apparently have just a 2840 mAh battery, but that's still an upgrade on the One M8's power pack and combined with a more efficient processor it could get the job done, especially as rumors claim HTC will be sticking with a 5-inch 1080p screen, rather than moving to QHD.
With the same size screen as the One M8 comes similar dimensions apparently, as the HTC One M9 is said to be 144.3 x 69.4 x 9.56mm, making it marginally shorter but actually slightly fatter than the 146.4 x 70.6 x 9.4mm HTC One (M8).
However, following the 5.5-inch and 5.0-inch rumors there's now talk that the HTC One M9 could meet them in the middle and have a 5.2-inch screen. That's according to Nowhereelse.fr, which even has images purportedly showing the display panel to back it up.
We also may have got our first real look at the HTC One M9, as two images of an alleged prototype have been sent to Nowhereelse.fr. The images show a device which looks a lot like the HTC One M8 or even the original HTC One, suggesting the company isn't straying far from its existing designs.
The front has speakers above and below the screen, while the back shows a curved metal shell with a camera and a dual-flash, though as the top of the phone has been cut off in the image it's impossible to say whether it's got a second sensor, like on the HTC One M8.
It's also hard to say whether they're accurate. They don't look fake and nor are they an exact match for any existing HTC handset, but they could easily be of an HTC One M8 protoype.
So we'd love for the HTC One M9 to have more juice. We don't think two days of battery life should be unrealistic, after all the HTC One M8 and a number of other phones can already comfortably make it into a second day, they just need a bit of a boost to make it to the end of the day.
If HTC can deliver even more than that then great, but we'd be happy with two days, at least until the M10 comes around.
A better camera
The HTC One M8 is great in low light as its lens lets more light in than competing smartphone cameras, but when you're trying to take photos in bright conditions all the extra light it takes in actually seems to work against it, causing the image to over-expose.
On top of that it's only got a 4MP sensor, which is fine when you're just viewing shots on your phone, but blow them up and there'll be noticeable noise.
So ideally we want more megapixels and a sensor which is as adept in bright light as low light. It almost seems like HTC itself might be moving away from UltraPixels, given that the HTC One Mini 2 and the HTC One E8 both have 13MP snappers, so we might well see a big change to the camera in the HTC One M9.
A QHD display
The HTC One M8 has a gorgeous screen, but it's very much an early 2014 screen, as the LG G3 and the Samsung Galaxy Note 4 are now bringing QHD (1440 x 2560) displays to the mainstream.
All those extra pixels don't make a huge difference but it is a noticeable one and if the HTC One M9 doesn't have a QHD display then it risks being overlooked, because you can be almost certain that the competition will.
A sapphire screen
Since we're talking about the screen, how about making it with sapphire crystal glass? The HTC One M9 is bound to be expensive, so many people are going to want to put it in a case to keep it protected, but it's also bound to be a thing of beauty so it would be a shame to cover it up.
The more durable it is the less necessary that becomes and a sapphire crystal screen would help a lot. The iPhone 6 didn't have one in the end, so if the HTC One M9 does it could also be the first mainstream smartphone to do so, which would surely be a big selling point.
Water and dust resistance
Another way to keep it protected is with dust and water resistance. We don't need to be able to take it swimming, but knowing that it could survive a spill or a bit of rain would certainly be reassuring and now that Samsung and Sony are both water and dust proofing their phones there's little excuse for HTC not to do the same.
HTC One M9: More of what we want to see
More of a health and fitness focus
The world is going health and fitness mad, or at least that's what many of the latest smartphones and smartwatches would lead you to believe. HTC though doesn't seem so interested and we can't help but feel that it's missing a trick, especially if the market for fitness focused tech continues to grow.
Sure a heart rate monitor and UV sensor are hardly essential components of a smartphone, but we wouldn't say no to them and we'd also be quite happy to see more of a focus on fitness software from HTC, rather than it relying on third party solutions, as HTC has done with the M8 by simply including the Fitbit app. Apple has Health, Samsung has S Health, HTC needs something.
Lots of power
It's reached the point where almost every high end phone and a fair few lower end ones feel fast and powerful, so we don't really need a lot more power in the HTC One M9.
But specs sell and while HTC's flagships are always powerful they're not always quite as powerful as the competition, at least on paper. So next year we hope that changes. Impress us HTC, put in an octa-core Snapdragon 810 with 6GB of RAM, or at least make sure your phone is a match for the Samsung Galaxy S6 and Sony Xperia Z4.
An even better design and build
Design is one of the things HTC has done best in recent years, with the One M8 rivalling even Apple's products, but it could still be better.
There's that black bar below the screen for example. On the original HTC One that housed some capacitive buttons, but they've gone from the HTC One M8 so it no longer serves any visible purpose. There may well be some internal reasons for it but we'd love it if HTC could find a way to remove it.
HTC could also improve the buttons, which feel a little plastic on the M8 and we'd rather have the headphone port on the top than the bottom.
HTC wisely added a microSD card slot to the M8, but we'd still love more internal storage. Apple now offers 128GB iPhones, so why can't an Android phone do the same? And more specifically why can't HTC?
Do that while still including microSD support and we could be looking at a phone with 256GB of combined storage, which is far more than most people are ever likely to need, but we'd rather have too much than too little.
Category 6 LTE
4G is taking off in a big way, but while current phones are equipped to support the fastest speeds we're likely to get in most places right now, they're not particularly future-proofed. That's why we'd like to see HTC put Category 6 LTE support in the HTC One M9.
That would theoretically allow it to reach download speeds of around 300Mbps, which is double what most current handsets can manage and should make it a viable handset right up until 5G arrives.