With the Mages guild breaking up before Skyrim and the college of winterhold being in winterhold obviously what do you think the next guild for mages will be? I'm not sure if there is a thread about this already and if there is I ask that a MOD delete it. I'm not too familiar with what happened after the mages guild disbanded. If someone could fill in on that as well I would be grateful.

Well the Synod and the College of Whispers took the place of Mages Guild after its collapse. The Psijic Order also exists, but they deal with magic in a different way than anyone else on Tamriel and also comparatively exclusive when it comes to admittance.

Those are the only known Mage organizations.