From what I've seen, *all* networks are supported out of the box. However, due to carrier locking, only specific carriers are supported. IE, to start with Tmobile gets support first, then the others. And Nokia won't have to do anything, save for changing the locking code. To do otherwise would be too inexpensive. It's the same reason you can only use the iPhone on the AT&T network, *UNLESS* you unlock it, and then it can move wherever you want it to. The same will be true of the n900.