Xbox.com has a content timeline for the week of E3. Now, it does not include the not announced material that you see in this list.
Personally, when I get home from school, I am going download crazy (got some good broadband at home). I am in love with the way that Microsoft has decided to use the marketplace. Forget about reading trailer reviews, or getting low quality video. I am getting HD videos that I can play on my HD TV at home. Rock on Microsoft!