There is one thing nVidia did better than AMD this round, and that's the idle power consumption. At first I was going to say AMD didn't do very well here, but compared to older nVidia card, they are not 'awful' (at least the 4850; the 4870 burn trees almost at the same rate as two 8800GT). Instead, the GTX 2x0 series seems to be exceptionally efficient on idle (the 260 matching a 8800GT, and the 280 matching a 4850).
Out of curiosity, can someone work out how much 45W (that's the difference between the 4870 and 4850 on idle going by Anandtech's measurements) @ 24/24, 365/365 costs at current price? [Note that I am not implying that the 4870 is a poorer buy compared to the 2x0 series, this is just an observation. That said, I would like to take this into account when selecting between the 4850 and 4870, especially given how energy isn't cheap or getting cheaper at the moment]