According to this Destructoid piece, Microsoft’s John Schappert is to keynote TGS. From the story:
The keynote will be hosted by Microsoft Corporate Vice President of LIVE, Software and Sales, John Schappert on Thursday, October 9 at noon. Called “A Canvas for the World,” Schappert will focus “at how Xbox 360 will bring more people together than ever before to enjoy the next wave of interactive entertainment experiences.”
Goody. More through the link.