A quick, moderately embarrassing update: it turns out yesterday's trailer for Terminal Reality's shooter The Walking Dead: Survival Instinct wasn't an official Activision production.
The hosting YouTube channel is not officially affiliated with the game, either. I should have twigged to that. It's a fair cop, gov. On the bright side, the trailer has had a lukewarm reception, to put it politely, so knowing it's not the real deal is somewhat comforting.
Survival Instinct is due in 2013 on PC, PlayStation 3 and Xbox 360, and is a prequel to the TV show following the adventures of Daryl and Merle Dixon.