I'm fairly certain this has been suggested due to the fact that the LoL community is huge. In either case, I'll bring it up again. I understand dominion and the upcoming magma chamber as well as aram/arab customs seem interesting, however I feel more variety is never a bad thing. I'm not entirely sure how balancing issues will work out, but I can just tell CTF will be popular given the chance.

I'll allow you guys to discuss how the CTF game mode should be game play wise?
(How many players on each side)
(Size of map)
(Various mechanics to avoid having unstoppable tanks holding the flag) - Debuffs?