FWIW: with wine from git from a couple days ago, here are wine build times on various Intel CPUs in seconds on Ubuntu 8.10's gcc-4.3.2 (or 8.04):
sec cpu wine notes 676 e7200 June http://kegel.com/new-computer-2008.html ubuntu 8.04 615 e7300 Nov 585 e7400 Nov (estimated, supposedly 5% faster than e7300) 540 e8400 Nov 360 q9400 Nov
In all cases, this was with the default optimization level, -O2. Compiling with -O0 was roughly twice as fast (e.g. 196 seconds to build on the q9400). The dual core e7300 and e8400 were tested with -j3; the quad core q9400 with -j5.
The current crop of CPUs is that they run cooler than older ones. Replacing the old Athlon 64's in the patchwatcher cluster with new CPUs and 80+ power supplies makes a big difference in the room's temperature!
The quad CPUs are coming down in price. Once you get used to fast builds, it's hard to go back, so don't try a q9400 or faster CPU unless you want to keep it :-)
Older benchmarks:
http://techgage.com/article/intel_core_2_quad_q6600/4 (is gentoo really that fast, or was he building with -O0?)
http://www.winehq.org/pipermail/wine-devel/2008-June/066121.html (q6600 386 seconds).