EDGE is based on GPRS (2G) and is considered 2.5G.
3G is UMTS.
Most of the operators are investing millions in 3G, as 2G will one day be obsolete.
O2 in the UK had to create an EDGE network especially for the iPhone.
That said, even without 3G, the iPhone is a fantastic phone. Email and web pages just load fine on EDGE and GPRS. Also most of the time I am at work or at home and I have access to WIFI.
As with most Apple products (and this can be true for B&O), if you just compare the specs on the paper they seem to do less, but when you use them, you see what it is all about.
3G iPhone will be available as soon as 3G chips that need less power are available
p.