2.4GHz is a "band" and not a frequency. If you research Wifi routers you see they are mostly channels of 1 to 11 (USA versions.)
As such, if they interfere, you change the channel.
Currently use linksys wireless router with laptops. XBOX is wired to network. I expect to get a 360 soon and would like to use the wireless controlers if possible. I believe the wireless controlers use the same freq. as the router so will they conflict?
I already had to buy different wireless phones to get them off the router freq. because they killed my laptop connections on occasion.