The one thing that really annoys me...
He's shooting first, so presumably, he will win the showdown in terms of being the first to define the character on film. Marvel has larger plans for the character, though, and wants to use him for more than just one action sequence.
A huge weakness with all the X-men movies are the characters that make an appearance just because of an action scene and are never mentioned again. Joss was actually going to make Quicksilver a prominent member of the Avengers. I really hope QS in DOFP doesn't discourage Joss from using QS and and Scarlett Witch in Avengers 2.