It looks like Microsoft is still going full steam ahead with it's plan for PC game retail domination... not only do they have Games for Windows Marketplace, but it's part of a larger picture for PC gamers that mean a lot to Microsoft.
I'm very vocal about this myself, Microsoft push DX11 and Windows 7 yet nearly all games produced are made on consoles first, then ported to PC with "DX11" - yet the game was created with DX9-esque hardware in mind (Xbox 360/PlayStation 3) - where the PC has all this horse power and untapped ability - yet, is not really pushed.
But, is this about to change? Group Product Manager, Peter Orullian has said that PC games "is a place where we are doubling down." What that meant exactly, no one knows, but there is only hope. Peter added "healthy list of features we're going to start bringing out once the store launches" - which was in response to a question about integrating PC and Xbox 360 gaming.