Ted Patrick has a great write up here.  This is what a lot of us MAC OS X folks have been eagerly anticipating for some time. In addition to support for Flex on Mac OS X, there are a lot of other great improvements (including support for Apollo  down the road), which again Ted has some more detailed information on. I just downloaded and installed the trial  without a hitch, now I just need to find out if I can use my Windows license on my Mac somehow. According to item #23 on the Flex FAQ  – “If I buy Flex Builder for Windows, can I transfer that license to Mac OS when it ships? Final plans are not yet in place; however, Adobe will work to put a simple program in place that meets the needs of our Macintosh developer base.” So I’m hoping we will get some more information on this issue soon. One more reason to become a switcher  if you haven’t already.
“If I am currently running Flex Builder 2 for Windows, can I trade-in my Windows product for the new Macintosh 2.0.1 product?
Yes. Customers who purchased the English language product via Adobe’s Volume licensing program should email firstname.lastname@example.org. Please include the following information in your email: AOO Order#; Order Quantity; Organization name; End user and/or Ship to user ID #. Please allow up to 5 business days for a response that will include your updated serial number for Mac platform.
Customers who purchased via the Adobe Store, please call Adobe Customer service and request a trade-in at the appropriate phone number for your region at: http://www.adobe.com/support/intlsupport.html. Customer Service will provide the download URL and a new Macintosh serial number to activate the product.”
Fantastic! Thanks Adobe for making it easy for us Mac users!
I was on hold for just under an hour when I called, and what I had to do was provide my existing serial #’s and they gave me a Case Id #, and then I had to fill out a Letter of Software Destruction for a Cross Platform/Cross Language upgrade  with the Cased ID # and other details and email that back to them. You don’t get serial #’s right away, you actually have to pay for shipping of a whole new copy that they will send out once the form has been processed. Shipping was no big deal at $6.36 – I’m fine with that, plus I get the physical media and manual to boot. Not a bad deal at all, and I’ll just continue to use the trial until I get the full product. So if you do plan to switch from Windows to Mac, go ahead and grab that form, have your credit card ready, and be prepared to be on hold for a little bit. Honestly not to bad a process, I know there have been a lot of applications over the years that I wanted to exchange licenses for a different OS, etc. and I can’t remember any time I actually was allowed to do it, so kudos to Adobe for allowing us to do so.