IF it's not an entire forgery: There will most likely be a large settlement here. The guy won't want to go through the legal troubles associated with the case since it will take years. He's not like Aaron or the twins, which saw more than just money in the case. Paul Ceglia wants his money. Facebook will also not want to go to court on this one as the PR drags out and there's a decent chance that something devastating could happen. The question is: What's the PR play? If FB settles for a large sum of money very quickly it will just add to the line of people that Mark "stole" the idea from.

There's also a chance that it's a forgery or gets thrown out on a technicality. Here's my somewhat logically, but still randomly decided likely outcome %s:

Facebook Settles For Large Amount of Cash: 45% The entire thing is a forgery: 25% It gets thrown out on a technicality: 30% Goes to court, Facebook loses (likely in 2012), devastation: 5%