If they are overly crass or stupid about it (like Beacon), then yes, users will get pissed. But, if they just got rid of those awful sidebar ads and replaced them with high quality, highly expensive ads for major brands, then I think users would be quite happy. Especially if the ads were highly targeted (based on user data) and the users found the ads useful or entertaining.

They really need to ditch those "click here to learn the secrets to being a billionaire" ads. They're just awful and they cheapen that ad space. The longer those ads run, the harder it will be for FB to get real advertisers to put anything worthwhile in there.