As far as I know there are none. I don't really see how it would work since the 360 has no mouse drivers, and the keyboard can only be used for basic text input (and it would be difficult to use the controller, which is two-handed obviously, and a keyboard at the same time).
Where does it say in the XBL contract that you can't use this? I'm not doubting you, I just want to see it.
Is it cheating? Some say yes, some say no...It's not like this allows you to do anything more than you can with a controller, you are just using a mouse and keyboard to control a controller. It's a godsend for people like me that have been playing FPS's on PC for 10 years but can't justify spending over $1,000 to build a new computer to play 1 game but can't stand using an ironically named "controller".
It's exactly like people who have the auto-fire controllers, it gives people using the XIM an unfair advantage over those who aren't (although my friends and I could probably still beat people using them). If using joysticks is to hard then go play on PC.