Clearly AT&T is trying to throttle their bandwidth to iPhone users.
Basically, yes.
Or to be more precise, AT&T is trying to monetize data usage so users throttle their own Internet use based on what their willing to pay.
As I said earlier, I too think $25/2GB is overpriced, but this will hopefully get better when other carriers abandon their old fixed rate "all you can eat" data plans. We shall see.
The upshot to all this will likely be a less reluctant high-speed data rollout, more emphasis on data efficient app development and possibly even some movement toward net-neutral carrier policy.(paid bits are paid bits, right?)
Sean