I just logged into the new Yahoo! Web Messenger, the webified version of Yahoo Messenger. It looks surprisingly (or perhaps not surprisingly) like the Meebo interface, with the exception of the advertisement panel featured prominently on the righthand side of the page. It also allows you to connect with MSN contacts, has an integrated search bar, and also has links to other core Yahoo! services (mail, My Yahoo, and Yahoo!). It also has integrated chat logging. I mean, this has a striking resemblance to Meebo — that’s all I am going to say on the overall UI.
For my tastes, I will still use Meebo and not just because I went to school with one of the founders. My friends are all on different networks and I like what Meebo is doing in terms of cross-network integration. I will be curious, however, to see whether Yahoo and other web-enabled chat providers continue to treat Meebo politely or whether they will change their approach as they roll out more web-based offerings.