Yeah, I think it's a pretty great move. Also that they're letting you out of contracts until the end of January is great.
I don't know how they're handling upgrades but if you can upgrade I'd go ahead and do it.
I don't know about the majority of plans being handed out but I've seen quite a few people get the $45/mo unlimited minutes, text and 4G data offer. With a phone payment, that would be about $70/mo for unlimited everything. If I could get that plan on TMo I'd probably switch.
But I can't, so...