I waited for years to switch to Mac full time because adobe is so expensive to re-purchase. With the new CS3 I had actually found myself on the phone with them trying to figure out why my PC kept on losing the registration data.
I figured that I would just ask if there was some kind of discount for switching to Mac, they then stated "no, no , no there is no discount" BUT I could do what is called a "cross platform switch" for 10 bucks.
A week later it was like dream come true, I got my brand new disks and then I got a new macbook pro and 8 core mac pro. Cant beat it for ten dollars.
Just in case someone somewhere is contemplating the move over...
Hope this helps. PM me if you need the number to customer service.