Facebook isn't clarifying things much: a spokeswoman reiterated to the Wall Street Journal that there wouldn't be any mingling, but also acknowledged that Moves would be sharing info. The truth, as Ars Technica suggests, may be complicated. While Facebook may not may be incorporating Moves' data with its own, the phrasing would let it pass statistics along to advertisers; there's a concern that companies might cross-reference Moves content with Facebook users and target their ads accordingly. If you start getting a lot of pitches for running shoes on your news feed, you'll know what's up.
Update: Facebook has cleared the air a couple of days later. Sharing simply means giving information to Facebook staffers so that they can help develop Moves and provide support. That data isn't going anywhere else, the company says.