The mod is going standalone.
Tough luck.
Either way it's started as mod -> game, so it's technically still not a game and I still don't see a
reason (huge story or anything) for it.
And maybe one day they will make a 'free roam' zombie game for the counsel, who knows. Every company knows a zombie game is the perfect game to make in this day and age as with everyone on "THE ZOMBIE APOCALYPSE!!!11!!!1"