Working pretty much fine for me on 2G unlocked to T-Mobile. Installed it yesterday, and twice it failed to send a photo - thought about it for a while, then said timeout error and moved the pic to the outbox. But then a couple hours later I looked at the springboard to see a 1 on the MMS app icon, clicked it and had a photo sent from my bro. So I tried to send the pic I originally attempted again, and again it failed, then all of a sudden it sent!
So looks like it is working, and saving the pic to the /100APPLE folder shows it in my camera roll aswell.
Windows (XP) seems to have taken it upon itself to set my iphone up as a digital camera, so everytime I plug it in it opens a transfer wizard to transfer pics from the phone to the computer, which is quite usefull