Homeworld works amazingly well under Crossover Games 7.0 on Mac. There are only the following 2 issues that I can find:
a: Doesn't work using the GL rendering option, but does perfectly well under Direct3D.
b: The cursor responsiveness for the in-game menus for building ships, setting up research tasks, etc., are very very sluggish.
Barring those two issues, the game looks and plays wonderfully.