A new version of the Microsoft collaboration and enterprise content management platform is in the works, and it will offer improved social networking, client and mobile UI enhancements, an app marketplace, and better cloud support. And that just scratches the surface.

It’s no surprise that Microsoft SharePoint is among the most widely deployed platforms for enterprise collaboration, with more than 125 million licenses sold to more than 65,000 enterprise customers. Right now, though, the mystery is all about what to expect from the next major release — and that’s rapidly starting to unravel. Microsoft recently released the first technology preview of the forthcoming upgrade, code-named “SharePoint 15,” to selected testers, and the company is gunning for a general beta release this summer. And while Microsoft isn’t saying, observers are betting on a commercial release by year’s end or in early 2013.