According to ESPN.com (Boston), a "source close to the situation" told Adam Schefter that Welker has torn both the ACL and MCL in his knee.  More testing and an MRI has been scheduled for Monday.

Source:
http://sports.espn.go.com/boston/nfl/news/story?id=4792582

Nauseating.  I have no idea how to feel right now.  The playoffs don't even seem relevant, I'm just sick for a guy who has been the epitome of a professional football player and a true New England Patriot suffering a severe injury like this.  No one deserves this kind of stroke of bad luck, but it seems particularly unfair for Wes, who embodies "shut up and play" like no one else.

While we can hold out hope the initial injury reports are wrong, no matter what the result I think every Pats fan around the globe is just hoping that Wes gets healthy -- not from a football standpoint, but for his life outside and after football too.