Me personally after reading abt the game in pczone would be:
1… Extra MP options like CTF or flag senario like in BF2…
2… Grapple like in Q1 ctf 
3… Short life lasting invisibility or cameleon style camouflage for stealth infiltration like in tribes2 for the generator or power source would be great…
4… Hand brake turns for small vehicles.
ps…when is the beta testing going to start i wanna play!!!