Given that [the iPhone 4 is already the leading camera in use by Flickr users](http://www.flickr.com/cameras/) this may seem like a no-brainer but I believe that, in a relatively short period of time, the iPhone 4S will be the most popular camera in the world.
A little over [a year ago I wrote about how it was getting very difficult to choose which camera to use](http://cdevroe.com/notes/iphone4-dslr/) in a given situation. The iPhone 4’s camera was good enough for almost every circumstance I had run into and so the convenience and speed of using the iPhone 4 over a DSLR made for a tough choice.
With the iPhone 4S that decision just got even harder. The iPhone 4S now has an 8MP f/2.4 camera that is also capable of shooting 1080p HD video (the iPhone 4 records in 720p). For any photographer that still pulled out their DSLR over the iPhone 4 they may find it a little easier to use the iPhone 4S. That is why I think the curve to popularity will be a very steep, up-and-to-the-right graph. More serious photographers will use the iPhone 4S then did the iPhone 4.
Time will tell if I’m right. I’d guess, 12 months.