Summoners .... what will they summon?

[Zantetsuken]

There are so many options. The new 2.0 artwork shows at least three candidates (Cait Sith, Fenrir, Typhon) and you could also add creatures like Ixion, Valefor, Espers from XII (considering Ivalice may appear in some form I don't see why not), etc.
Old bosses could turn into summons as well so there's a lot of material available.

The art of Fenrir, Typhon, and Cait Sith could be a very strong indicator that SMN job is VERY close. And as you state, there are a lot more 'lesser' summons that would be good candidates for the job: Carbuncle (almost certain), Quezacoatl or Ixion, Valefor, Golem, Valigarmanda, Brothers, Tonberry King, Syldra, Catoblepas, Quetzalli, Midgardsormr, Bismark, Mist Dragon, Lakshmi, Siren, Unicorn, Seraph, etc..

As far as FFXII Zodiac Espers/Classic FF bosses. I'd like to see them in the game inhabiting a tier above the Primals. Summonable? Maybe eventually... but make them more rare and difficult to summon than even Primals will be.