What jobs are we hoping to see in the next expansion?

[Videra]

Being frank? Unlimited BLU. But that's a little iffy.

Realistically?

We know the tank will be gunblade/soldier/judge, whatever you want to call it. The healer will either be GEO or DNC - DNC hype is at a peak right now, and GEO was heavily set up throughout the course of SB1.

[Valdegarde]

Being frank? Unlimited BLU.

This, more than anything.

Also, while I'm not sure whether people will like it or not, there's an option for Dancer and Geomancer to be aesthetically combined like Bard and Ranger or Thief and Ninja are. (Viking and Berserker too?)
One of the reasons Geomancer seems less likely is that it is currently set up to be an Astrologian/Conjurer counterpart, however Mog used dances through geomancy, and is the only real recognizable Dancer job character in the series, aside from maybe Penelo (and possibly whomever in XI too.)
Yet this also leans on "limited job" territory, as Mog learned his dances almost exactly like a Blue Mage, except by fighting in different environments instead of the enemies themselves. I do wonder if the fanbase reaction to Blue Mage and limited jobs has scared them off from going this route ever again though, with the possible exception of actually crazy jobs like Onion Knight, Mime, and Morpher.