The Android 5.1.1 update still hasn't arrived for devices (except for Nexus devices that have received a "factory image"), but it looks like owners of the brand new Samsung Galaxy S6 and S6 edge have something good to look forward to. While the cameras of the said flagship devices are already considered the best in the market, there is still some room for improvement. And it seems like the mini-update to the Android Lollipop will bring a few more enhancements to the cameras.
However, the early 5.1.1 ROM that some have access to doesn't seem to contain these enhancements, which probably means that the build isn't that final (or that their sources may be wrong?) The rumor is that the camera improvements will include support for the Google camera API. So that means you will have the ability to shoot in RAW format and also have control over the shutter speed. Other competing flagship devices like HTC One M9 and the LG G4, have these features built-in already so Samsung will definitely need to have these features.
There is also a report that says these new camera features will already be part of upcoming new devices codenamed Samsung Zen/Samsung Noble. This apparently refers to the upcoming Galaxy Note 5, which will be launched later this year. Things are still in the very early stages, software wise, so we won't be able to know or have more credible news that that is indeed part of the upcoming new member of the Note flagship.
Meanwhile, let's wait and see whether the camera of the Galaxy S6 and S6 edge will be further improved when Android 5.1.1 rolls out. There is still no news when that will be, but hopefully it will be sooner than later.