Though I have another suggestion to be working on, I've been thinking about it for a while. I'll leave it simple.
Instead of being teams, there would (obviously) be everyone for themselves. You are STILL capturing points, however, but just one point. This makes it like King-of-the-Hill. The reason for having FFA be like this is so area control weapons are still viable. (Outright fighting throws bombs to the dust.)
There would probably be maps for 4 and 6 players. Each player would have a spawn area, though it would be small.
There is probably some major flaw with this, but I'm not going to do any deep searching because...meh already said why.