I found Twitter to be useful for arranging meetings (mostly dinner), no question on that. The commentary on the rest of the event was a mixed bag, but I'd say a lot of it was interesting too, though if adoption really spread I'm not sure it would remain usable as the noise level would be high. I think it might be interesting to have someone from PASS monitoring the various tags and retweeting things that are of value to most attendees, that way someone could get the raw feed via the tag or just follow the PASS account and get a more consise view.