The support notice mentioned, “As part of the recent Xbox 360 system update, Microsoft Points will be retired and the Xbox.com PC Marketplace will be closed as of August 22, 2013. We encourage you to spend your Microsoft Points balance prior to this change. Although you will not be able to purchase new games, you can continue to enjoy previously purchased content by downloading it through the Games for Windows Live client software as usual.”
Of course, this particular upcoming change would not see the demise of Games for Windows Live, only the ability to purchase games via Microsoft’s store. The Games for Windows Live service will still continue to operate normally, so you can breathe easy there now, gamer.