AnandTech published a battery life analysis on why the Apple iPhone has no 3G:
Apple's stance is that the iPhone gives you a slower than 3G solution with EDGE, that doesn't consume a lot of power, and a faster than 3G solution with Wi-Fi when you're in range of a network. Our tests showed that on Wi-Fi, the iPhone was able to pull between 1 and 2Mbps, which is faster than what we got over UMTS but not tremendously faster. While we appreciate the iPhone's Wi-Fi support, the lightning quick iPhone interface makes those times that you're on EDGE feel even slower than on other phones. Admittedly it doesn't take too long to get used to, but we wanted to dig a little deeper and see what really kept 3G out of the iPhone.
Pointing at size and power consumption, Steve gave us two targets to investigate. The space argument is an easy one to confirm, we cracked open the Samsung Blackjack and looked at its 3G UMTS implementation, powered by Qualcomm..