Apple's next iPhone is already guaranteed to be a blockbuster hit.
Piper Jaffray analyst Gene Munster surveyed 400 consumers and found that 65% expect their next phone to be an iPhone. Of these, 51% said they were specifically waiting for the iPhone 5.
Moreover, Munster's survey found that 94.2% of iPhone users plan to buy another iPhone for their next phone.
Munster says these two data points suggest that as many as 80 million iPhone 5 sales are already "in the bag," as he puts it.
"We believe this suggests that as much as 50% of our estimated iPhone units for FY13 are in the bag (~170 million iPhone users x 94% re-buy x 51% iPhone 5 planned purchase)," Munster wrote in a research note on Tuesday.
By comparison, Munster estimates that Apple will end up selling ~125 million iPhones in total throughout the 2012 fiscal year. That's for all models, not just the iPhone 4S.
Munster predicts that the blockbuster iPhone 5 sales should help Apple increase its share of the smartphone market to the low 30% range by 2015, up from the low 20% range right now.