Z-Ray Vision
A brand new perk, allowing you to see Nasty Zombies through walls. Incredibly useful for tracking down that stray zombie, especially if you're going for a speed record.
I See Dead People
A new achievement has been added in conjunction with Z-Ray Vision.
In other news...
With the addition of another perk, that brings the total up to 10. The base price of perks has been reduced from £200 to £150 to account for this.