S.W. - Scarlett Witch
Q.S. - Quick Silver
These two will be in the Avengers 2. But i have trust that Whedon will make things make sense, because well these two characters...are Magnetos kids. YES HIS KIDS. And its really odd because anything X-Men movie rights belongs to FOX. But apparently Marvel/Disney can use them at some extent (hard to explain with in the lines). BUT! They are not allow to make any reference of them being mutants and or relations to Magneto.
And I believe Fantastic Four is owned by FOX? Because I know Dare Devil, Blade, and I believe Punisher are back in the hands of Marvel.
GotG - Guardians of the Galaxy
MCU - Marvel Cinematic Universe