Personally, I'm not a big fan of dueling, but if it does eventually make it in the game, I have a suggestion for introducing it in a way that would be less likely to kill the group PvP in Cyrodiil:
Make the arena in say, Imperial city, and restrict it to the two factions that own the most keeps in the ring around it. This would mean that only two factions could be having duels at one time, but might give a boost to the third faction in group PvP (since the other two factions would have some of their members occupied by the duels and so unable to participate in the group PvP). So the third faction couldn't duel until it took keeps.
Just a thought.
Templars are 'just slower... by design'
Yes, Gina actually said that (at least regarding Rushed Ceremony) right here:
http://forums.elderscrollsonline.com/en/discussion/161959/templar-skills-bugged-made-useless-ignored/p24
VR 16 Templar (retired until Templars get fixed)
VR 16 Sorcerer
38 Nightblade
24 DK