Extremetech reported that T-Mobile is making a huge leap in 2012 to upgrade its network to LTE, meaning that not only will your devices work faster, but that devices like the iPhone and iPad that ran originally just on AT&T will be able to operate on T-Mobile without significant hacking involved.
Sure, I’ve just hacked mine…oh well. If you’re looking at jailbreaking and hacking an iPhone from AT&T, you might want to wait as for some models doing so reduces it’s functionality in some minor – but not insignificant – ways. But it may be a long wait and the switch won’t likely happen until 2013. But T-Mobile is definitely the winner here, as it cost for the jump is being handled mostly from funds it received after the botched buyout from AT&T.