I've been wondering 'round with the new G1 Android phone and can definitely find areas where the connection throttles back to EDGE. In fact I can walk from one end of our office in the AT&T Building to the other and move between an HSDPA 3G connection to the slower EDGE wireless.
This doesn't surprise me hugely; it is, in fact, the nature of wireless, particularly when T-Mobile US Inc. is still switching on its 3G network. I suspect the situation will get worse when I return to Brooklyn for a well-earned nap this evening, particularly as my apartment has nice thick walls.
Nonetheless, I'm not overly concerned; I expected that this would be the situation before I bought the device, in fact. Wireless is never ever 100 percent in my experience.(See Hot or Not?, 3G iPhone Connection Complaints Arise and Man Bites Phone.)
— Dan Jones, Site Editor, Unstrung