I'll believe there will definitely solo movies not that is a Wolverine solo when I see it. In my opinion, nothing has really change. They could have already given Deadpool/X-Force a release date but instead, we are getting another First Class film in 2016 and a Wolverine film in 2017. And if that reserved 2018 release date is for X-Force or Deadpool, why keep it a secret?
Now to the OT cast, the producers always consider making more films with the or at least bring them back in some way (like cameo roles). I do think the success of DOFP will lead them to make another movie with them.