The reason for the 8 pin connecter is because that PSU is more for a highend server running Dual CPU's or Dual Cores. Most (Dual Core) ready MOBO's for the desktop are being made with 8 pins on the MOBO.
As for using it in a high-end gaming rig, it's not really over kill. Think about all of the OCin' World record holders. They all seem to have some beefed up 1350watt custom PSU. Put it this way, configure the highest end PC for gaming. Then add major overclocking to that. Now you're using it for what it's supposed to be used for in the desktop. A freakin' power plant... lol
Yeah it's pretty much overkill... lol