CS @ Stomped has posted an interview with gooseman. This is some very juicy stuff, drivable vehicles will be in BETA 7 (this is not fake, I've talked to Gooseman about it also):
Go check it out! What this means for the release date is unknown, but the build with vehicles has not been tested at all, and should push the release date back a few days at least. Stay tuned.<Sebastian> Can you tell me something about the vehicles in Beta 7?
<Sebastian> What are the gonna be like?
<Sebastian> ATVs, Trucks?
<Gooesman> Whatever the mapper likes
<Gooseman> The just move like func_tracktrains
<Gooseman> But you can steer them anywhere you want