Much as I would like this book simply for the options contained within, I have made a decision to only purchase 4E books that will be opened to the GSL, at least at full cost. I doubt WOTC will open any of the content of this Player's Guide to the GSL, and so I won't likely pick it up. Now, if they do add some of the gaming bits within to the GSL (no product identity, of course, just mechanics), then I'm all over picking it up.
At the moment, knowing little about 4E and only the blurb above on the Player's Guide, I will likely wait until I can pick this book up cheap (second-hand or in some other form that is no more than half the cover price) and go from there.
With Regards,
Flynn