Digital Reality announces Dead Block, calling this a "unique" zombie defense game for Windows, XBLA, and PSN to be released "later this year." The Dead Block Website has images and a trailer, and here's a bit on the Unreal Engine 3 game:

Dead Block focuses on innovative defensive gameplay in which the few remaining survivors, Jack Foster (a construction worker), Foxy Jones (a traffic warden), and Mike Bacon (a perpetually hungry boy scout) have formed an unlikely alliance to protect themselves from the invading undead. Hiding in various shelters around town, they avoid Zombies by building blockades, setting fiendish traps or – as a last resort – using their weapons to fight.

In addition to 10 Single-player levels the game offers up to 4-Player, Split-Screen Multiplayer with an additional 8 Multiplayer co-op levels where players can fight side by side with their friends.