Let's get PVP totally reworked. It's unplayable as it is. Would love to see guild v guild wars in it, and not have us lose points every time we log out.
Also, new maps (Antarctica!), and some military units for survivors like a mortar launcher that could destroy spawn points but also occasionally misfire and destroy your own spawn point.
Really anything to shake it up, the game play is getting too repetitive and guilds are losing great invested players that have gotten bored but say they'll come back with an update. Let's get them back!