Yes, you can do a cross-platform upgrade. Check the Buying Guide on teh product page for details.
Thanks Mylenium. And the Mac doesn't reject the Windows product code from the previous version...?
With a Cross-grade, you will get a new Mac S/N.
Good luck, and be sure to check out all the info on the product pages.
If you upgrade to a Cloud License you can have CS6 on both your old PC and your new Mac.