Actually I'd love to see a separate arena. Not huge, nothing fancy in the way of terrain.
But with ALL the evil con mission planes and perk planes available for free.
Even if it only showed up once a month for a few days. Going in there you would know, this is the "Evil" arena.
Anything can, and will happen. Fly here at your own risk.
So you could have a shark vs shark duel if you wanted.
Or you could try the flying PT boat, or the 20mm sheep from heck.