Well, again, the original poster has already mentioned the two most well-known solutions for the newer Mactel platform...
The reason for running Bootcamp, at the moment, is so that you can have both kinds of machines running on one platform. And since you're turning your system into a dual-boot system, rather than running multiple virtual pc's or macs across your processors, I would venture a guess that for the purposes of running a fairly processor intensive audio program, it would make the most sense to want to run one OS at a time.
However, the Parallels program is pretty nice, and inexpensive, and allows you to drag and drop files from your PC environment right into the Mac environment, and vice-versa.
Considering that Bootcamp is free...I'd go that route if you want to try running Audition on your Mactel, before you go off buying anything.
Rock on...
mb