Codeweavers makes Crossover Games, a commercial version of Wine that allows you to play various Windows games on Mac and Linux:
Based on the latest Wine Games development work, CrossOver Games allows Mac and Linux users to run their favorite Windows games in the environment of their choice. No rebooting, no switching to a virtual machine, and no Windows Operating System license required; CrossOver gives you the best performance possible if you’re not running on Windows.
Now they have a page where their registered users can vote for them to arrange Fallout 3 support on the application. Thanks Patrick.
Filed under: Bethesda, Bethsoft, Entertainment, Fallout 3, Fallout3, News Tagged: | mac and linux gaming

I’d say it’s better to use the open source Wine and do bug testing there instead of trusting commercial companies to do the work.
Check out Wine’s support for Oblivion: http://appdb.winehq.org/objectManager.php?sClass=version&iId=5777
I know this is an old thread, but I’ll point out that Crossover is a “good citizen” in the open source world. One of their employees is the maintainer for Wine: http://www.codeweavers.com/about/people/julliard
Making it work in Crossover will inevitably lead to it working in Wine.
Really old blog post, but still thanks for the info Cameron.