I'll just add that T-Mobile recently unveiled a new prepaid plan on 10/16 (for us in the US)

$30 monthly gets 100 minutes, unlimited text, 5GB 4G, 2G access thereafter. From my understanding, prepaid doesn't get roaming, but the coverage is nearly identical (96%?).

Possibly new customer only at this point. If I could port my number, I'd probably try it. I don't talk much, nor use much data (mostly wifi coverage). The extra data would be more useful than extra minutes to me.

Sounds like a decent deal IF you find a cheap phone off contract, and you don't use many minutes. Of course if the AT&T deal goes through, I wouldn't expect this to last.