While a native port would be nice, SeeYou runs fine under VMware Fusion and Parallels Desktop for Mac.
Last time I checked, SeeYou ran without support for 3D features under CodeWeaver CrossOver (a commercial Wine port to OS X) and it runs fast doing so and requires no Windows License. I've not used it enough to really be sure there are no problems.
Fusion and Parallels require a Windows software install/license and are likely the right approach if you also have other programs you need to run under Windows. 3D performance is better in Parallels, even with the new OpenGL support in VMware Fusion.
You can also of course also use BootCamp, but rebooting is a pain.
CrossOver -
http://www.codeweavers.com/products/cxmac/Fusion -
http://www.vmware.com/products/fusion/Parallels -
http://www.parallels.com/computing/I exclusively use SeeYou on Windows XP running under VMware Fusion on a Mac BookPro 17".
And don't forget we'll eventually want an iPad port as well.
Darryl
SeeYou 
