We have just released a demo of Zombie Driver for all those that haven't had their chance to drive through the masses of brainless undead.
The demo features the first 3 levels of the story mode.

We have also started work on a new Survival game mode that will soon be released as free DLC.
Players' skills will be tested against waves of zombies on a new set of specially crafted arenas.
The new game mode will be accompanied with Steam online leaderboards and achievements.
Further game play details will be revealed soon.

Along with the demo we have released a new patch that fixes several technical issues.
Change log for version 1.0.6
- updated shaders to support most Intel 900 & 950 series graphics cards
- fixed problems with some unique combinations of special characters for user installation path in Windows

Change log for version 1.0.5
- fixed startup crash bug with diacritical signs (special characters) for user installation path in Windows
- added memory dump logging after each crash

Great news! I love the Survival game mode, sounds like fun :D

I do have a couple of questions though...

1. Are there any plans for a multiplayer mode? either a co-op mode where two players can do extremely difficult missions together, or a 'duel' mode where two players battle and show off their Zombie killin' skills :D

2. Are there any plans for an official editor? And by Editor I mean a tool that will allow us to modify the city and create new missions.

1. Not this time, sorry. Maybe in the sequel if we make one...
2. Currently there are no plans for that. Our tools are extremly user unfriendly and to make it work we would have to release stuff that we simply can't. (for many reasons)

I really enjoyed Zombie Driver, so I'm really looking forward to the new Slaughter Mode.

Any idea when it will be released?

Most probably in two or three weeks from now.