Not sure if this is old news to any of you, and if it is you should be shot for not posting it here!
But you can now download the RE5 demo (which was only released in japan) rip it to a disc, and play it on your 360!! Now im not gonna provide links, you can find everything you need using google!
Directions:
Find the demo and download it!
Copy the folder from the download onto a disc. (roxio, nero, w/e you got)
Disconnect your 360 from the internet.
Load the disc into your 360.
Go to your demos and it will be there!
ENJOY
AND NO YOUR 360 DOES NOT NEED TO BE MODDED TO DO THIS!!