Ask YC: Can twitter-like products go mainstream?

Looking at a product like Twitter, which is seemingly a news feed rip-off, I'm hard-pressed to see a product like that going mainstream outside the tech world. Same with pownce and others. Now to be successful not everyone has to use the product, that's not what I'm saying, but I think there's a tendency in the tech community to think that just because a product is useful or meaningful to us (because we spend so much time online, sharing our thoughts and wanting to be connected) doesn't mean mainstream users want or need it. Can ___________ (fill in the blank with web 2.0 derivative) go mainstream?