if anyone can buy lion on app store if u are on GM press ALT when i click buy and let's u buy it i use this method and works
I just did this, but I don't think it charged me. It's downloading in the same spot in my purchased list as my old GM version (which had already changed it's name to the release version), and my purchase date still says Jul 1, 2011. So, now I'm not sure what I'm even downloading - the GM Seed again, or the retail release - or if there is even any difference or how the h*ll to tell.
Apple needs to clarify this confusion for developers who have installed the GM to save a lot of potentially unnecessary downloading and installing.