In the crude sense of collecting all your posts and sending them all to an advertiser, of course not. In the sense of selling your interests, friends, social position, age etc to advertisers as a datapoint, yes they do; that's how they target ads and make money. They also tried to harvest purchasing habits from other sites like Amazon (with Beacon), and give broad access to developers, some of whom abuse the privilege and have been caught selling data on. I'd expect that sort of activity to increase post-IPO. They're not alone in this of course - gmail does the same, without the data lock-in.

No, they do not sell interests to advertisers. What they do is allow advertisers to show their ads to people with those specific ages, interests, and such. It's a subtle and important difference: with this method, advertisers only know that their ads are being shown to someone who matches their criteria, not who. Advertisers are not able to correlate your identity with ad targeting.

They don't have to, they sell access to it. Why would they sell it when they can basically rent out time to access it?

No, they sell services using it. Advertisers and others who give Facebook money do not see user information; they just pay to leverage it for effective targeting.

Do you work at Facebook? :)

I think you're missing the point. Facebook doesn't have to hand out a text file with your name and a list of all your friends for it to be considered "selling your data".

It's considered "selling your data" when you go to an unrelated site and that site gives you customized content based on information you gave to Facebook.

That does not happen either; user data is not given to third parties. I do not work at Facebook; however, this has been clearly and repeatedly stated by them (including, I believe, in legal filings).