No 3G on the iPhone, but why? A Battery Life Analysis @ AnandTech
 

*Source: AnandTech (http://anandtech.com/gadgets/showdoc.aspx?i=3036)*
____________
Most of the initial reviews of Apple's iPhone shared one complaint in common: AT&T's EDGE network was slow, and it's the fastest cellular network the iPhone supported. In an interview with The Wall Street Journal, Steve Jobs explained Apple's rationale for not including 3G support in the initial iPhone:

"When we looked at 3G, the chipsets are not quite mature, in the sense that they're not low-enough power for what we were looking for. They were not integrated enough, so they took up too much physical space. We cared a lot about battery life and we cared a lot about physical size. Down the road, I'm sure some of those tradeoffs will become more favorable towards 3G but as of now we think we made a pretty good doggone decision."

More...