Did you try calling tech support for Linksys, i just think most people have Windows and that is why the CD is for Windows, I would think the product would work on Mac, it just needs to be setup differently.
I would try calling Belkin and tell them you are looking at getting that model and ask them how to set it up on a Mac. i never set mine up on my Macbook as I had airport express already in it.
i just recently replaced my wireless router, i bought a Belkin N and the cd would not set up in my desktop which is Vista, but I called and they walked me through manual setup, my Mac was able to detect it through the network profiles, so I would assume using that USB wold be a similar setup