I think AT&T's plan is to catch up with and overtake the other wireless companies(but isn't that always the plan, lol?). They were the exclusive retailer of the globally-revered iPhone for a while, but the other guys had the jump on 4G and a variety of cool devices from other manufacturers.
Now that everybody's got the iPhone, AT&T is trying to build up their faster, but seriously limited 4G network, to keep up with the Joneses. I'm happy, yet at the same time a bit sad that AT&T is coming out with some sweet Android smartphones nowadays- happy 'cause I love Androids, sad 'cause I can't port my unlimited data plan along with my phone number from VZW to AT&T. Cest la vie.