Stage 1: Social Networking will adapt Bitcoin for micropayments. Speculation will drive value to one or two orders of magnitude.
Stage 2: Commerce will embrace Bitcoin as an overlay mechanism, like Paypal. Speculation will drive value one or two orders of magnitude.
Stage 3: Bitcoin will replace local banking for businesses enjoying low fees. Local legislatures will officially recognize Bitcoin. Speculation peaks.
Stage 4: Nations will begin to decouple currencies and adapt Bitcoin.
Stage 5: Nations and corporations will merge as they lose their competitive advantage over decentralized enterprises.
Stage 6: National borders will dissolve as decentralized enterprises evolve into AI driven civilization planning.
Stage 7: Bitcoin will evolve into a scientific-method based algorithm using Asimovian principles.
Stage 8: Ebil robot zombies will eat our brains and conquer the Universe.
While i personally would love to see your stages come to pass (especially the zombie one) I do not think they will. Stage 0 is obviously already happening. Stage 1 however seems VERY unlikely, as long as social media is dominated by Facebook. Facebook is developing their own credit system, and have no reason whatsoever to accept bitcoins. As your whole plan really depends on stage 1 for launching, none of the other stages will come to pass either. Even if facebook is derailed by google+ or perhaps some other unknown player, what incentive would they have to allow bitcoins and not adopt their own version of facebook credits?
I thought about physical Bitcoin possibly added to Stage 1 to help boost acceptance to stage 2, but I'm not sure that they will get beyond collectors items. Getting Bitcoin out of the hands of geeks and on the streets will be tough.
I think that the outcome your stage 1 would achieve (greater btc acceptance) could well happen, just not necessarily through social media. There is still that thing called word of mouth you know