I originally had two plans on two iPads, but I don't use enough data enough to justify it.
I ended up giving one to my mom. As a backup internet device, it works wonders and is easily worth the 30 bucks a month just to not have to do tech support right away if her internet goes down.
I ended up selling the other one on craigslist. Now I'm wondering if I should have kept it to give to some other old person in the family that needs internet.
Yeah, I killed mine about a year ago since my use was so low. Still never go over 2 GB, but the "feel" off being unlimited was nice. I think the trend is that unlimited users are diminishing so AT&T isn't worried about. Based on posting on the iPhone forum, it seems there are a lot more iPhone unlimited users, which AT&T does throttle.