Shall I discuss a heresy? What about the twitter ecosystem?

This evening, as I was helping explain how to use my Palm Pre to another Pre owner via twitter, I began to think about how to share a visual (via twitpic.com), count my followers (via twittercounter.com), connect in a video chat environment (via tokbox.com) and I wondered: if twitter finds that elusive business model, how will the ecosystem survive?

Are we building a twitter bubble?
I am flashing back to the 90s when everyone was building portals because "eyeballs" were king (because you could monetize them), then there was the ecommerce / eMarketplace growth that lead to very few successes, then there was the blog bubble (which had a few successful exits, but primarily was a publishing play) and then, lets not talk about the podcast bubble that left thousands (is it 50K publishers, tubemogul?) And our most recent growth spurts of organic, vertical search tools and social networking platforms - why am I not surprised what is next?

Two years ago, when twitter was just being used by a few hundred thousand users, there was a big discussion on what twitter's business model would be. But I think the question now is - how can twitter do a similar model where they provide a social good AND generate a revenue stream that benefits all who leverage it and sell services from it.

Case in point - look at the ecosystem from RSS and blogging and podcasting. With the lovely gift of RSS being the thread that supports syndication, the major player in the space (feedburner), got absorbed with it little revenue stream, into the mother ship. Modeled after the fremium service model, feedburner might demonstrate what the companies with traffic that offer compelling service (like Summize) can look forward to.

But what of the not so lucky ones?
My fear is the story of all tech companies that do not hit the exit. They either whither (or whimper) away and die or the sell to the best bidder to share their IP and staff or become zombie companies. Those are the ones that I hope take Nate Westheimer's tack and place their company/code in the hands of the Open Source community.