It would be great to have more PvP modes I feel. So I guess here we can discuss some ideas?
Capture the Flag:
It could have 5 different maps, each with a red team and a blue team and 2 flags, 1 for each base, in the middle of both bases. Get the other team's flag and return it to your base to score. 3 points to win.
Any other ideas you guys can come up with?
Also there could be a mode like battlefield's conquest mode. Where there is a defending and attacking side and 2 "levels" of capture points. if the attacking team captures the first 2, they move on to the next 2 and if they capture those next sets, the game ends. With the defending team respawning on a cycle every 20 seconds (so lets say you die die at 10 seconds and another one of your teammates dies at 15 seconds, you respawn in 10 seconds while your teammate respawns in 5 seconds) And the defending team can respawn on a cycle every 15 seconds. And the defending team can spend CE on gun puppy turret stations to help defend them and whatnot.
Lockdown IS conquest, except the it counts up. Your thinking Rush mode.
Cart pusher, a'la TF2.
Single-flag CTF, where you fight over a single neutral "flag" and try to take it into the enemy base.
DotA style arena, with "minion" monsters and gunpuppy/polyp/howlitzer turrets. Even just adding challenge buffs to the current lockdown game mode might be interesting (aggro and slay a group of neutral monsters to get a temporary bonus).