Before I bought it, I had a good look around at the various forums and reviews, and the general opinion was that, unless you're getting into at least watercooling, or some sort of extreme cooling, it's great for the Conroe chips, but not the best choice for the Allendales, due to their lower multiplier and therefore need for a higher FSB.
I have a Conroe rig, using the P5WDH D and an Allendale rig using a Gigabyte GS3, which I've pushed up higher than my P5W DH's 380 FSB. I've not tried the P5W DH seriously any higher than 390 because my E6600 was getting too hot under the Ninja. So i have no idea personally how it copes under faster FSB settings. Xbit reckon it tops out at around 420, which would give an overclock to 3.78GHz.
edit: yes it would creed, but nobody knows anything about when/if it'll ever happen, or what it would entail. It seems to be all speculation at the moment because as far as I know, intel and nVidia haven't said anything substantial about it, unless anyone's heard something I haven't.