NBC's website doesn't have much yet, but I found the below press release and a slightly longer trailer. There's a spoilery review of the pilot on Futon Critic. Also, it appears that IMDB shows exactly how many episodes each actor is in, so just be warned that it's probably spoilery as well!
From Academy Award-winning writer Christopher McQuarrie ("The Usual Suspects"), who is executive-producing with Heather McQuarrie, and executive producer Rémi Aubuchon, comes "Persons Unknown," a one-hour mystery drama in which a group of seven strangers must come together to solve the puzzle of their lives. All of the seven strangers have been taken from their everyday lives and have arrived in a deserted town with no recollection of how they got there.
The eclectic group of strangers are Charlie Morse (Alan Ruck, "Spin City"), Janet Cooper (Daisy Betts, "Shutter"), Joe Tucker (Jason Wiles, "Third Watch"), Bill Blackham (Sean O'Bryan, "Six Feet Under"), Moira Doherty (Tina Holmes, "Six Feet Under"), Sergeant Graham McNair (Chadwick Boseman, "Lincoln Heights"), Tori Fairchild (Kate Lang Johnson, "Days of our Lives"), Erika Taylor (Kandyse McClure, "Battlestar Galactica"), Mark Renbe (Gerald Kyd, "Casualty") and Kat Damatto (Lola Glaudini, "Invincible"). While being held hostage, they are watched constantly by omnipresent "security" cameras with no idea who or what is behind them and every attempt to leave is thwarted by unforeseen circumstances, which seem to derive from mysterious forces. At every turn, these strangers-turned-comrades are threatened physically, psychologically and emotionally.
Their only option for survival is to rely on each other, but whom can they trust in this vulnerable state – either behind those cameras or amongst themselves? Their decisions will have moral and ethical consequences, as alliances are forged and relationships brokered.