Just thinking out loud here.
I had some ideas for other gamemodes. Here they are.
SWARM - You have a given amount of time (Say, a minute and a half) To grab some weapons, get in position, make a plan with your teammates, etcetera. Then, all hell breaks loose. First tens, then hundreds, and thousands of weakling enemies pour into the arena. Maybe like tiny, fast zombies.
TEAM SWAP - Basically TDM, but when you die, you switch teams.
GLADIATOR - Tourney with Gauntlets only.
JUGGERNAUT - One player is selected to be the "Juggernaut." The Juggernaut is equipped with all guns, 2500 (Or so) health, Infinite ammo, etc. If you are NOT the Juggernaut, you need to work with everyone to kill them. If you ARE, you need to kill everyone. No respawning.
Anyone else have any ideas?
Sounds like ideas taken directly from other games; as Team Swap is Red Rover in Quake Live (as Fromhell stated), Swarm seems like just a server option (like instagib), Juggernaut is just Quad Hog (+) in Quake Live and Swarm is just DMSP in Sauerbraten or even Red Eclipse.