The aa-12 is cool but it is old news. I wonder why the discovery channel is talking like they are state of the art. The AA-12 and the Striker or Protecta have been around for nearly thirty years. They are tremendous weapons but nothing new. You want to see something groundbreaking and I really think this guy is on to something check out this
http://www.youtube.com/watch?v=iX7vwivR6cE. If he gets some backing under an arms contract and smooth outs the cycling this will be the most feared squad automatic weapon available in my view.
As for the Cheytac .408 they were big news a couple years ago. I am still a J.D Jones man myself. That video of them shooting is not nearly impressive as Carlos Hathcocks shot on an NVA soldier at 2500 yards with a M-2 Browning machine gun. Much more impressive of a feat considering how much slop there is in a heavy machine gun compared to a bolt action rifle. Also the fact he had a 10 power Unertl compared to what looked like a Schmitt and Bender tactical in the video it could have been a Nightforce though don't qoute me. Definately looked like Badger Ordinance rings though.
Cactus if you are looking at a sniper rifle have you checked Accuracy International or Surgeon actions? They are awesome weapons and even the old reliable Barrett is hard to beat.