Yeah I used to have trouble reaching 1 GB, but since I got into podcasts, Pandora, and HBO, my data has skyrocketed. I will switch to Sprint if they still offer unlimited data by next May. If I'm able, I'll switch earlier. Sprint gets pretty good Android phones anyway- I guarantee they get the Galaxy S3 and the next Nexus(es) before Verizon. I really need unlimited, even if it's throttled. I can't imagine being paranoid and counting how many minutes I've been on Pandora and such.
I doubt the super-data hogs are even the problem. Like someone else said, they're probably trying to squeeze more money out of that 5-10 GB user, and with LTE I gather that is quite a number of people now.