Most initial docs Ive seen have suggested that the cap will be set at 2 or 5 gigs.
I really dont think this is going to be as much of a big deal as some of you seem to think its going to be.
I hope youre right. You probably are right. I consider myself to be an average user and Im at 673446.68kb and my usage resets in 3 days. That would be $75.00 at the 150kb for $15 rate and most people wouldnt pay that (I HOPE!).