The game will run in parallels, not fantastically, but will run. I'm trying a windows 7 VM and it's a little jerky on my 2.5ghz quad core i5/16GB RAM/HD6750, but I'm sure those with slightly beefier specs will find better performance, and I can probably make some efficiencies on the win7 install to eek out more performance.
Booting into win7 via Bootcamp, and the game is as smooth as Ive seen at 1080 res and high gfx settings.
I would hazard a guess that a WINE or CIDER version would run at pretty close to native Win7 speed. I've managed to run the launcher, patch and watch the intro FMV's under WINE, but thats as far as things go, and I dont know enough about WINE to work out the next steps.
Why bother ?
Well, as much as I loved windows 7 and my PC, I think Lion is a fantastic OS, and I find most apps I need to run work faster and more reliably on it, and I just plain prefer the look and feel of Lion to Windows.
I would much prefer a native version, but even a working Wineskin/CIDER wrapper would do if it worked well.
Until then, I'll do the solo, no hassle stuff, under Parallels, and the serious gaming in Win7 until another option comes along.
This isnt about Windows vs Mac, or "my OS is better than yours", it's about the fact that Mac use is increasing very fast and there are a large number of people running them that would love to be able to play the game in the OS they prefer.