For friends that need to measure manliness a dueling area would be sweet. Maybe use the iron banner area for challenging ppl to duels as an interact option. Just make lord saladin appear or vanish as nessicary. Just a thought.
As long as the game has free for all in the crucible I'll be happy. Not really a 1v1 player. Borderlands 2 dueling does not need to be in Destiny.