Long-term ATT'll have better coverage, but for now, not so much. Basically they (that is, existing ATT customers) get T-Mo's 2G/EDGE network, but that's about it. 3G is still on two different channels, so ATT/T-Mo customers are still split there. ATT's 4G network is nonexistent, while T-Mo's is brand-new and tiny. Moving forward, as they build out 4G, this is a net win, but the merger doesn't help anyone's 3G coverage.

Ugh... I hate this. I really don't want to be an ATT customer.