Snow Wolf Commando Unit (Beijing Special Police) are premier Chinese SWAT unit and will be the behind the scenes at the Olympics.
The QBZ-95 rifle
Type 79 SMG (7.62x25mm)
If is interesting to see the Type 79. Gun.ru:
Type 79 submachine gun is rather unusual for its class as it is very lightweight and uses locked breech, gas operated action instead of more traditional (for SMG) blowback action. This weapon was (and probably still is) widely used by PAP (Chinese police).
No doubt these guys will be quelling the protests against Chinese policy that could break out.
A lot more photos here.