Microsoft is notorious for keeping things proprietary. However, the upcoming Guitar Hero III game will feature controllers using their proprietary wireless standard.
This is big news because this will make Red Octane the first company that Microsoft has allowed to use this wireless technology. This will give us new Les Paul guitars that don't require any cords or adapters.
I'm really looking forward to these new controllers, I can't stand the X-plorer for my 360, I'd much rather use my PS2 controller any day.