The only reason I see why bitcoin will not work as the ultimate currency used by all is simple:
When all the bitcoins are minded there is no possible to way to get any more, nobody will want to spend anything because it will ultimately be the most valuable thing, and besides how the hell do you handle a deficit or surplus when everything is being done in the same currency and nobody can make more of it.
Ultimately we come back to the gold standard that had the same exact problems and blew up. The only thing i can envision for bitcoin in the future is to make online trading more efficient, but seriously there would have to be an unlimited number of bitcoins to solve the golden standard problem.

Your thoughts, let the flames begin!

I'm going out, so have fun with my share guys

With my predictions at the latest in April. That's based on the previous trend bitcoin has had, but it will strongly depend on how the market will develop, and if we have some big player come into the picture. Though the trend now certainly seems positive and it is true that bitcoin follows a hyperbolic curve since the more people know about it they tell more people etc. etc. The only real danger bitcoin can face is if some government decides to ban it or seize it, or if a better alternative comes along.