2) A lot of people still aren't buying smart phones because they're really expensive. It looks like U.S. smartphone penetration in general is around 50%: http://www.google.com/search?q=smart+phone+penetration+unite... , and most of them don't have cameras nearly this good and won't for a while. People who can afford a $50 – $200 pocket camera might not want to pay more than $100 a month for a smartphone data plan.
3) That being said, the smart money is definitely on the low-end pocket camera going away over time.
4) High-end cameras, even pocket ones (think the Canon S95 or S100 class) are going to be around for a long time. Ditto dSLRs. Until the laws of physics get violated, dSLRs are going to take vastly better pictures than camera phones. Which doesn't matter to most people but does to a substantial minority.
Will that happen? Seems likely, given current trends - phone cameras like the 4S are (nearly?) good enough now, I think.