As far as I understood the idea, flashn00b suggests to have the Chaos Duel gametype with its melee weapons instead of regular arena fights. Chaos Duel includes various melee weapons (the user can select one of them for duelling) with complex movement. Basically you not only click to "fire", but your movement also comes into play when deciding the actual way to swing the weapon. There are also three different stances (light, medium, heavy), which further affect the speed and strength of the attack. For example when jumping forward in heavy stance and starting the swing near the peak of the jump, a good central hit with a heavy weapon (e.g. a large axe or hammer) has the potential for a one-hit-kill. Moving left or right while attacking results in horizontal swings, which are not as dangerous as the "death from above", but are much quicker, and so on.
Arena fights like that could cetainly be an interesting addition.