The good part is that it's sort of like being in a giant chat room with your friends and a handful of 'net-savvy celebrities, all just chit-chatting about whatever comes to mind. It's a nice way to "keep up" without having to jump through the logistical hoops usually required for direct person-to-person contact.
The bad part is all the stuff that you might expect to come with that, not the least of which is 50 people all going "OMG SCANDAL!" about every stupid thing that bubbles up in the media or on websites that cater to any given person's hotbuttons. You know those annoying e-mails that people forward without thinking, the ones asking for prayers/donations for a sick little girl in Utah or that spew political yakkety-yak? The ones your mother keeps sending you even though you tried to train her by sending her the Snopes article debunking every one over and over again? Yeah, Twitter can be like those, but in real-time.
So, it's a mixed bag. I'll keep hanging out there for a while, but I'd say there are even chances that at some point I'll just get sick of the whole thing and drop it.