Microblogging will have made it when we dont have to depend on a single centralized provider to work. The system needs to be naturally distributed and handle partial failure, everything similar to email.
That's one possibility. The other possibility: when we all shut up about Twitter, it won't because it's become an unconscious tool. It'll be because it's a long forgotten fad.
The article title is a bit misleading: because it suggests a naive thought process (because Twitter <i>depends</i> on buzz for it's value).<p>But the actual point he makes is very valid: which is that when Twitter becomes an unconcious tool then it will have "made it" (w/e that means).