Microsoft’s announced today that it now supports sharing documents within Facebook Groups. Microsoft’s Fuse labs brought to Facebook back in April, but the service hasn’t necessarily taken off, in part because sharing documents with a specific group was unwieldy, as you had to add people manually.

Now promises integration into Facebook Groups, something that wasn’t previously possible for third-party apps. Users can share documents within a Group for others to view or edit. Updates to will post a story to the Group’s Wall as well as to the newsfeeds of its members. And you can leave comments about documents on the Group Wall or within the document itself.

You don’t need to have Microsoft Office installed to use, but the system only supports Word, Excel, PowerPoint and PDF file uploads.

I had a few problems test-driving the integration this morning. I couldn’t get new Docs to post to a Group’s Wall, and it looked like the Group selection defaulted to the first alphabetically, even if you’d set the Doc up for a different group.

Hopefully the bugs will be worked out over the weekend, as the announcement today dovetails nicely with what’s expected to come from Facebook on Monday. Facebook is set to hold another press event, where it’s rumored that it will launch an email platform of some sort. According to ZDNet’s Mary-Jo Foley, Monday’s announcement is rumored to also include integration of Microsoft Office Apps into this new email system, much as occurs with Hotmail now.

Today’s blog post from describes this as “one giant step toward our vision for social productivity,” and “social productivity” is may well be the key theme for Monday’s Facebook press conference.