Well taking into consideration of a few comments and responses, we will most likely see THF>NIN (or Scout>NIN) in 1-3 updates after the release of 2.0 (maybe longer depending on the number of glitches and major issues that need fixed, along with people needing new endgame content after 2.0s release)

The idea was to bring 1 to 2 new classes before 2.0 (which may or may not change.) and more after 2.0.

Yoshida mentioned more mage classes 1st, but recently asked which classes people would want 1st.

Ranged Mage DD/debuffer
Beast Tamer/Summoner Buffer DD
Scout/Ninja DD

People mainly voted for pet, then ranged mage DD/debuffer, and lastly Dual Wield.

So I would assume a similar level of popularity will be across the other forums, leading Yoshida to work on THF/NIN last (I wanted THF/NIN as well)