Ok so it works but suffers from a bit of a frame-rate hit.
Ironically my less powerful Macbook Pro Laptop gets a better frame-rate than my main desktop Mac Pro.
The frame-rate issue is present throughout the main menu screens as well as in game.
It is playable (Just) on my Mac Book at least but it's somewhat annoying.
The other thing is that it wont let me play this with my Wireless Xbox 360 pad like I can in bootcamp.
So if anyone can help me in this department I'd be very grateful.
I use a special driver for my pad whilst in Mac OS X http://tattiebogle.net/index.php/ProjectRoot/Xbox360Controller
This driver seems to work with with all my other control pad games I run in crossover so I asume thats not at fault here.
System Specs
Mac Pro 8 Core Xeon 2.8ghz
Geforce 8800GT
OS X 10.6.8 CX 10.3
Mac Book Pro i7 2.66ghz
Geforce GT 330M
OS X 10.6.8 CX 10.3