Well, this is weird. We just got an email inviting us to a by-invitation-only announcement by Facebook and MySpace scheduled for 12 noon Pacific time on Thursday.

That's like receiving an invitation to a party thrown by the New York Yankees and the Boston Red Sox.

Scheduled to participate are MySpace CEO Mike Jones and Facebook VP of Partnerships and Platform Marketing Dan Rose.

What's this all about?

Given that Facebook CEO Mark Zuckerberg isn't listed as a participant, it doesn't seem like it would be a HUGE announcement, like some sort of joint venture or merger. (Plus, MySpace is listed first.)

Is MySpace throwing in the towel and moving its social network over to Facebook's social graph, to focus on being an entertainment portal? (With MySpace contributing entertainment content to Facebook, or something?) MySpace has no future as a social network -- we logged in the other day for the first time in months, and were amazed at what a mess the place was -- so this isn't a terrible idea.

Or is the MySpace "log in with Facebook" deal just getting some play for the press? (If you sign up for MySpace right now, you can log in with Facebook.) This is already live on the site, so it couldn't be a big unveil, but given the characters involved, it wouldn't be surprising.

Something else? Have a guess? Let us know: tips@businessinsider.com.