We have to new articles up on the AMD Athlon 64 Venice core upgrade, that I first took at look at here

HotHardware has reviewed the the Venice 3800+ model processor, but didn’t find a lot of overclocking room. 

Lost Circuits takes a much more detailed look at the power consumption of the new core in their review of the 3800+ model

At the same speed, the dual stress liner technology used in the Venice core is supposed to yield approximately 24% power reduction. What we see here is an 11.1 % delta but keep in mind that we are looking at the Veince core running at 2.4 GHz and the Winchester core at 2.2GHz. If we factor in the additional 12% power delta for the clock difference between 2200 and 2400 MHz as taken from the Clawhammer results, we end up with a 24.3 % power savings for the Venice core compared to the Winchester core (using the 29 degree Celsius reference point) which is consistent with the IEDM white paper.