Capcom's released a Resident Evil 6 demo to Live, but it's only accessible if you bought Dragon's Dogma.
To access the demo, go to Xbox Live Marketplace and redeem your code written on the back of the Dragon’s Dogma manual to begin the download.
You then need to start Dragon’s Dogma, "and awaiting you is our personal thank you in the form of early access to what we think is the best Resident Evil yet," according to Capcom Europe's blog.
The demo is exclusive to 360 for two months, and will launch on PS3 on September 3.
The Dragon's Dogma promo was announced in February.