I give Apple a lot of hurt, but here they fixed something big and nobody else seems to have noticed. Even better, by fixing it they put more hurt on a deserving AT&T.
A few months ago I wrote about iMessage use on an AT&T iPhone without a SIM card (iPod Touch mode) using .me accounts. Problem was Message/iMessage 5.0 wouldn't let me enter a .me account in the iMessage app, nor would it show .me email addresses. I could only iMessage my son from the Contact UI. From Message.app, since he's on H2O wireless rather than AT&T, I could only initiate a conversation using SMS (20 cents for me, 5 cents for him).
I'm still on iOS 5.0 on my phone , but my son is on 5.1. So I could see than on his phone I can enter email addresses (the keyboard has a '.' now) as well as choose a .me address -- all from the Message.app UI. I've now updated my phone to 5.1 and it works there too.
It's a significant enhancement, but I don't think anyone else noticed ...
 I was concerned it wouldn't work with MobileMe, and I've yet to switch to the inferior and problematic iCloud alternative.