This morning we announced Socialtext 2.0. Techcrunch has the story.
This screencast gives an overview of the first major enhancement, the UI:
Charlie Wood highlights the second part, Wiki Web Services.
In addition to UI enhancements, SocialText 2.0 adds what the company is calling "Wiki Web Services", which are a full set of both SOAP and REST APIs to enable integration with other applications. I've signed up for the beta program and will be expanding my work with Salesforce.com and Google to include SocialText as well.