Killing Floor - Zombies in the UK

[Azazel]

http://www.killingfloorthegame.com/2009/04/29/pre-purchase-starts-plus-a-trailer/

$20 on steam, but they have a 25% discount for pre-orders.

6-player co-op, persistant perks, etc. System specs are low enough I could get some friends playing potentially. The write-up looks promising, but a real shame there's no playable demo.

[NiX]

It doesn't look appealing and there's no demo. I don't think it's going to ride on the coat tails of L4D.

[Hayduke]

It's based on a UT2k4 mod, so maybe that's the demo heh.  Doesn't really look like it has a lot of character and charm like L4D.  Looks more like it's trying to be a co-op Doom.