There are a metric shitton of 7.1 surround sound gaming headsets in existence. They fake it, mostly, with virtual surround sound. Razer's Tiamat 7.1 headset, though, pushes surround sound into your skull with 10 discrete drivers.
Which Razer says makes it the "first true 7.1 surround sound gaming headset". Each ear cup has five drivers, as you can see in the handy diagram below. The big idea is more precise positional sound -- obviously, you'll need to be playing a game that supports 7.1 -- but ideally when you're getting shot in the arse, you'll hear which cheek the bullet went into.
Is that worth $US180? Maybe. You'll get a chance to decide later this year. [Razer]