Assuming you can install Wine on a mac (CrossOver is the commercial version of Wine), it can be done.
This is all done through linux, but it should hopefully apply to OS X as well:
Once you've installed Wine (preferably the newest version via source code, but if there are Mac packages/executables available, give those a try if you'd prefer the easier route), install the games. The installer works flawlessly under Wine.
After they're installed, open a terminal and type "winecfg". In the Applications tab, click "Add Application", then navigate to the install directory and select BGMain2.exe. After you've done that, go to "graphics" and set it so that it's emulating a virtual desktop - whatever size you pick is up to you, but I go for 1024x768. It doesn't make a difference really, since the game is always shrunk down to its native res.
A final note is that if you're having issues with sound as I do, make sure to kill any applications that might be using sound... media players, music organizers (itunes), web browsers, etc.
All of this applies to Torment as well, and presumably future IE games.
Now to try this GemRB thing.