Oh GOD I didn't even realise Jennifer Lawrence was also in this :o

The follow up film is called

 

X Men: Days Of Future Past

Release Date: May 2014

 

Its based on the 1981's comic stripped Days Of Future Past in which an assassination in the present must be averted to prevent a shocking future where mutants are kept in camps and hunted down by giant robot Sentinels, with Patrick Stewart returning in a cameo appearance.