I've been too busy playing Street Fighter IV over the weekend to do a proper update here, but in my absence looks like the KOFXII Premier Event went down over the weekend with out a hitch. Here are a couple links with all the updates:
Dengeki.com posted some new images showing Duo Lon who has been added to the roster earlier this week.
Cyberfanatix.com posted a bunch of new videos and images form the event along with a rundown of the Critical Counter system that is found in the game.
Video showcasing the Critical Counter system thanks to Cyberfanatix YouTube Channel. Check their channel for more match videos from the event.
After reading up on the system, if I understand it correctly you enter a Critical Coutner state when intercepting special moves from mid to close range with a strong or medium (normal?) attack. This allows you to chain together "whatever moves you choose" (custom combos?) or if you time it right perform a Desperation Move (super).