I really think this pricing is actually pretty fair. And when I look at my actual usage on attwireless.com, I see that this pricing won't really affect my bill that much.
In December and January, I used around a gig of data each month, meaning that my bill would be only $5/month cheaper.
In February and March, I used 2.1 and 2.3 gigs of data, meaning that my bill would be $5/month more expensive.
And in April, I used 1.2 gigs of data, making my bill cheaper.
And in May, I only used 0.7 gigs of data, once again making my bill cheaper.
I think ATT really could have screwed us with pricing, but I find this to be completely fair.