Hyper threading? That's partly what made the P4s run as hot as hell with only a small performance increase. HT isn't any kind of replacement for 2 more cores.
My hopes aren't high for nehalem's HT. But the P4s with HT ran hot, and a 45nm won't run as hot as them so HT will be better than the P4s but not enough to match a quad core penryn. I think. All speculation
