FUD Zilla reports Intel's Atom processors with DDR3 support will have a 6.5W TDP:
While the upcoming Atom N450 and N470 processors are supposed to have TDP ratings of of 5.5W for the 1.66GHz clocked N450 and 6.5W for 1.83GHz clocked N470, the new Atoms supporting DDR3 will have a TDP of 6.5W.
Even the 1.66GHz clocked Atom N45x with DDR3 support should consume 6.5W of power because the new memory controller combo design wants more power. This fact becomes very interesting as DDR3 memory needs less power, but the new memory controller wants more. The bottom line is that the power consumption and battery life of Atom N450 / N45x series processors with DDR2 and DDR3 memory should be very similar with only slight variance.