Just wanted to throw my 2 cents in as it relates to the new data plans. The spread of the two data plans from AT&T is really odd. I can burn through 200MB in less than two weeks, and that's with nothing but web browsing and e-mails. 2GB is about twice what I will ever use, since I only use 3G at work and mostly rely on wifi.
So in my situation the only real choice is either no 3G or the $25 plan. I know there is an option to stick with unlimited, and I guess at $5 a month it's not that expensive to hold onto, but I honestly can't see myself ever going over the 2GB threshold. So why not save $60 a year?
At least that appears to be true based on my actual usage patters which I suspect will be more common than not.