Yes... let's all do our best to screw the carriers. It's obviously AT&T blocking it because if it was available, the company would lose millions of dollars while people exploit the unlimited use of data network to use it.
Watch your network quality and phone subsidies (on ALL networks) drop to holy hell because everyone with a smartphone lowers their voice plan to the lowest thing possible and uses Google Voice instead.
As much as everyone likes to hate them, they need to make money too. They especially need to make money so we can all enjoy our little smartphones and complain about why network upgrades (which cost hundreds of millions, if not Billions of dollars) aren't completed quicker for us.
There's no such thing as a FREE lunch... someone pays for it. In the end, the consumer will suffer for being cheap pricks. Like the person that walks into a cell phone store and gets the Free phone, and then wonders why it sucks so much and stops working right after 7 months. Cheap is expensive.
The really bad:
If we take advantage of the carriers TOO much, they might start charging by the minute for data instead of letting us use it as much as we want. They'll make their profits somehow... but we'll all pay for it big time.