There are problems with CDMA/EVDO though. The big one is that you can't use the data network and voice at the same time. This is a limitation that does not affect AT&T and their 3G network.
They can already overcome this limitation. It is built into the CDMA Rev A. spec. The problem is that the carriers didn't put equipment in place to support this feature. So, from a realistic perspective it's the same as if they never added the feature but it is available.
