Great news! Personally, I'd like to see Cannonball, Sunspot, Blink, Warpath, Boom Boom, Wolfsbane (and whoever else). Hopefully it would be set in the present time, so we could get some OT cast as minor roles (trainer/instructor).
This opens up the "New Mutants" team to be a core X-Men franchise going forward. Have their headquarters somewhere different than the mansion too--San Francisco, or maybe even Muir Island. Would love to see Genosha too.
My hope is
2016
Deadpool (set in present)
X-Men: Apocalypse (set in past)
Gambit (set in present)
2017
Old Man Logan (set in present with cameo/supporting role for OT)
New Mutants (set in present with cameo/supporting role for rest of OT)
2018
X-Force (with Deadpool, Gambit, Cable, Bishop, Domino, & whoever)
2019
X-Men: Apocalypse sequel
Essentially, keep a trilogy going in the past--it seems that in X-Men: Apocalypse they'll have more than enough characters introduced that they can play around with for plenty more films.
But also continue in a present/future time period. Wrap up most of the OT cast with Wolverine 3 (perhaps Stewart, Berry & Paquin??), and again with New Mutants (I'd love to see Beast & Shadowcat as trainers/instructors, and even Stewart as Xavier again here too)
Deadpool & Gambit will build up the rest of the mythology and, then, take advantage of the shared X universe by having the characters cross over into X-Force.
You could even bring the 1980s cast into the present down the road and mimic All New X-Men. Yes, it's time travel again, but that is something that sets it apart from other current CBMs on the market (plus it'd be going forward in time, rather than back as in DOFP).
That way, FOX has 5 X franchises and a universe right there