Both games are said to be in the hands of developer DoubleSix, although its website has no mention of them. Perhaps an E3 announcement on the way?
Sony Slips Two New PSN Games
15 July 2008 | By AndyA
Sony has let slip the names of two new PSN titles in development on its website. The list of games compatible with the DualShock 3 controller includes the previously unheard of ‘Burn Zombie Burn’ and ‘Underfire’.