This is not Adobe. Just user to user.
But this is the way it goes as I see it.
If you can show proof of ownership of a Premiere Elements 8.0 serial number, that should make you eligible for "upgrade pricing" for the Photoshop Elements 12 Mac and Premiere Elements 12 Mac combo IF you purchase Adobe's online download of these products from Adobe, not an authorized reseller. Please see the following Adobe document to see if you read it the same as I do.
Photoshop Elements 12 and Premiere Elements 12 will each have its own serial number.
Note: You get the same product from an Adobe direct purchase whether marketed under "upgrading pricing" or "full".
If at some time afterward you decide that you want Photoshop Elements 12 and Premiere Elements 12 on Windows, you would have to make a new purchase.
But, if you purchased Photoshop Elements 12 and Premiere Elements 12 in boxed packaging from an authorized reseller, then the combo purchase comes with an installation disc for Windows and another installation disc for Mac. The pricing would be controlled by the authorized reseller and is often less than the Adobe "upgrading pricing".
Any questions or need clarification, please let me know.
Best contact Adobe Sales in the link provided to get official Adobe Sales pronouncement on this.
Thanks so much for the informative response! Gosh I didn't even think of a combo Mac/PC pack. It appears to be way cheaper than an upgrade. I'll look into doing that. Thanks again!
Thanks for the reply.
Last year when Photoshop Elements 12 and Premiere Elements 12 were released, I was going to buy from Adobe direct but decided to do otherwise when I learned that Adobe direct was selling only the online download files rather than the box packaging which would contain both Windows and Mac installation discs. At that time, Adobe was making available the boxed packaging but only through its authorized resellers as I understood the situation.
The Content download situation for Premiere Elements 11 and 12 are as described in the following blog post.
Reminder, if history repeats itself, Adobe should be releasing a new version of Photoshop Elements and Premiere Elements at the end of September 2014. No one but Adobe knows the feature set.
Best wishes for whatever your video editing program decision is.