The first batch of Marketplace content has (mostly) gone live. For your downloading pleasure, the following is now available.
DOA X2 E3 Trailer (Japan)
Project Sylpheed Trailer (Japan)
Tenchu Senran Trailer
Half-Life 2 - Episode 2 Trailer
TGS Picture Pack
Tenchu Senran Demo (Japan)
There are also map packs available for BFMEII, though one of them -- Aragorn's Journey -- is supposed to be free, it's not working correctly right now. Don't download it or you will be charged. The other pack -- Northern Badlands -- is not supposed to be free so, you can grab it for 350 MS Points if you want. Also, as of this writing, the Half-Life 2 - Episode 2 trailer doesn't seem to be up.
We're not really sure if this counts as TGS content, but several XBLA games have been updated to take advantage of the Vision camera.
360 at the Tokyo Game Show:
HD-DVD for $170, $250 Core w/ Blue Dragon
1080p for 360!