AT&T is reportedly optimizing its EDGE network ahead of the iPhone, according to Gizmodo.
EDGE is slow, but at least at AT&T, the implementation isn't limited by the protocol itself. Rather, the limiting factor is, according to our source, the data backend and the way the towers are configured to allocate bandwidth to data and calls. And according to an internal doc, they're dropping in more T-1s in their poorest performing towers, hoping to get that paltry 40kbps performance to a new minimum of 80kpbs. (EDGE's real world max is about 200kbps.)
The iPhone can perform web browsing from either EDGE networks or faster 802.11g WiFi networks when in range.
While 3G capabilities can be expected in future models, the tuning of AT&T's EDGE network looks to maximize the user experience for early adopters.