And it looks like Brotherhood will have a beta. Yep, a multiplayer beta (although most singleplayer betas aren't betas, are demos, but whatever..)
During a Q&A section concerning Ubisoft's recent financial earnings, Ubi's CEO Yves Guillemot confirmed that the upcoming Assassin's Creed game would have a open beta test. His actual words were "We have not announced exactly the date yet, but yes, we will have a beta test."
While he didn't specifically said "We're having an public open beta test of Brotherhood, people!", he did confirmed a bate period, and mentioned that a date for it to happen to be announced. Closed betas don't have announcements dates, they don't even need to be confirmed since it's a game essential step of development.
Anyway, Guillemot promised that more specifics would be announced at E3, which will take place from June 15 to June 17.