yup, though the 65nm part is 576mm, the 55nm is unlikely to be smaller than 450nm, probably closer to 500 than 450nm. Its supposed to be a 16% drop half node in size from 65 to 55nm, if you get lucky and everything lines up better than at 65nm, you might save some die space, if it doesn't quite shrink perfectly(which considering this was supposed to be out 4 months ago and has taken several respins to even get out) you probably will get less than a 16% die size reduction which will put it at a little above or below double the size of an ati core. Power per square MM is far higher on the ATI core, because its half the size, thats really where cooling largely comes into play.
But Webby is also right, its also down to ATi's quite strangly and stupidly low fan speed at stock, you can bump it from 25%(where it hangs for me) to 37% or so without really being able to hear it anymore but get a decent drop in temps, up to 45% and you get a ok drop and not to much noise 50% fan and you'll go from 95c load to 70c load but will be fairly damn noisey.
THe thing is ATi fans are by default very slow which does result in high temps which ISN'T a bad thing, just isn't a great thing either. I haven't seen mention how loud the 295 fan is, it might be 3 times as loud and thats why its cooling better, I really don't know.
Either way, I'm going to sue someone next gen if there aren't some 4850x2 style heatsinks on the cards from release, or at least someone gets a 3rd party cooler out for next gen cards basically on release. its ridiculous waiting 6 months for a cooler only for the next gen to be almost upon you