I do think it would be interesting if some PvP map had some situation that forced you to use melee. Kinda like from Aliens or something, the map has some objective near a reactor core and for safety reasons all ranged attacks are disabled within that area. You must use bat'leths, hand to hand or rifle melee.
Also amusing would be a "pistols only" area.
Maybe some maps could simply issue you temporary equipment -- your real inventory simply gets hidden and all you get is what they provide you. Here's a pistol, here's a bat'leth and they shove you through the door.