Gone, replaced by something better that doesn't require constant hashing/wasted energy and ASIC computers to keep free. The smartest people in the world are not yet even involved in Bitcoin. Bitcoin is leading the way, but I doubt it'll be the end all solution.
Pretty much this. The way I see it, Bitcoin will do to currencies what Napster did to music sharing online: It'll change everything, then fade into relative obscurity. But it's impact will be felt for a loooooong time.