From Om:I can see why IAC would want to build something like Meebo around their network, or even FIM. I can certainly see how Meebo fits into a great ecosystem of services beyond IM. Their services right now may only work within the meebo.com site, but you can bet that the web service integrates easily within other existing web offerings that already aggregate IM information (think: eBay, Friendster, MySpace, etc.).
Here is the rub: Since the company basically aggregates all four major IM networks in a browser, all the four major IM owners - AMYG are out of the acquisition game. One of them buys the company, the others shut down access to their respective networks. The very quality that makes Meebo attractive to end-users will make it difficult for them to be acquired. But there is one option: eBay. When all fails, you know who to call. Skype did. Interactive Corp is another long shot, but they are bargain hunters not premium payers.
The other aspect of this is that they've built a nice framework for building other apps. Some 90% of the screen space on meebo goes unused. Does it make sense to have a web-based desktop environment that provides you with other offerings? I don't know. But I can think of a dozen things I would add to that interface that would extend the application well beyond IM (think email, konfabulator widgets, info trackers/RSS, etc.).
What's also interesting to me is that no one has brought up Goowy yet -- someone else that is also playing into the web desktop space, but in a much more flash heavy way.