but not games that just have gfwl tacked on that you buy at retail?
You're not the only one who's confused here!
This confusion stems from the fact that there is GFW-Live and GFW-Marketplace, and MS seems to use the names interchangeably, but they aren't the same thing... at least I don't think they are!
For instance, when trying to download the GFW client here, the page tells you that you're downloading the GFW-Marketplace client, whilst the file you download is gfwlivesetup.exe.
& only applies on games released after 15/11/2010
thought it was all one and the same thing.