Bluetooth headsets work great with the system. Most people are using one of the cheaper Motorola models such as the H300 or H500 models. Myself, i have a headset made by Plantronics. Haven't made that much use of it yet though (don't get into the online play much).
Most headsets should work with minimal set up. If you were planning on getting Warhawk you may want to save your cash and buy the Blu-Ray version- it is coming bundled with a bluetooth headset.