when a Spiderman reboot does more than 700m worldwide, its not like Sony was really sad to see those numbers, u know?
So many studios wish to have the first movie of a new series doing that well.
The issue is how profitable each new series can be in the Long Run,
not just with the first movie.
And lets see how the sequel does, I wont be surprised if it breaks the 1 billion mark, and even if it does around 700 again, its still a big hit, so Sony wont stop there and will do a third one.
Next Big X-Men Crossover
* 2017- X-Men: Age of Apocalypse
Edit: Forget about 2017:
Official announcement -> X-MEN: APOCALYPSE - MAY 27, 2016!!!!