if this is a $100 card for real and ends up being around the £70 mark inc vat its a pretty huge win for ATi, if they can make it noticably lower power than a 4830/4850 aswell it could make for an excellent cheap gaming card in a pretty low power rig aswell, assuming 40nm isn't as crap as the rumours say.
Thing is I'm guessing its designed to have 640 shaders rather than being a 800 shader card cut down to 640, meaning other than being 40nm its also a much smaller die design anyway, and 128mbit bus with gddr5 leaves cheaper pcb's, small cores and less traces which all helps.
best case scenario is they've basically taken a 4850, reduced power, die size, production size, less complex pcb's, and dropped the price what, by 1/3 or so. Not bad at all. is the 8800gtx/9800gtx/250gts basically a little slower than a 4850 card at the moment and costs more? meaning the newly rebranded cards will be similar speed but be probably 50-60% more than the cost of a new lower power cheaper to run ATi card?
), and Zalman coolers on them as well (so wonder if they'll become the norm). 
