Ask Cryptic the NPC's and playable races have different mechanics and as such with the NPC'S they are limited in what they can do where the Playable races have full rang of motion and abilities. I thought it was a bunch of BS but thats what the word is. I just think they are stalling for something down the road.
meh at this point a comment along the ines of "maybe" or "would be nice to do" is good enough for me.
While anything is certainly possible. Remember we're committed to bringing the KDF as close to par as is humanly possible before we add another faction to STO.
We're also fairly certain at this point that the next playable faction will be Romulans.
As for Undine joining Starfleet as a playable species, that would be very interesting...
Which is not to say that it won't happen at some point. But there's no plans right now.
Really unorthodox suggestion for factions following the completion of Klingons and addition of Romulans:
While I really, really want to see factions like Cardassian and Ferengi added down the road (and think they should eventually), I kinda think you'll get a lot of energy and enthusiasm out of something more exotic, that combines the subfaction idea you've discussed before with the idea of another faction.
Remember how the Future Enterprise (the 1701-J) in Enterprise had Klingons and Xindi?
I say, work up a crazy future faction that includes Borg and Undine (how crazy would it be if the feuding Spock and McCoy rivalry of the crew was a now cordial but adversarial banter between an Undine and a Borg), Cardassian and Photonic, Klingon and Human.
And this faction is neutral (even friendly) with everyone else... and gets to play "time police" by insuring everyone else's missions succeed.
Basically, a 29th or 31st century faction that gets to include all the wacky stuff that doesn't belong anywhere else, is helpful to everyone in PvE and can choose sides in PvP.
I think you'd build a lot of enthusiasm and, done right, could add shape to STO's narrative.
Maybe just cram it full of races that don't make sense. Playable Horta. Human-Tribble hybrid. Just stuff that is exotic and out of place in the present.
Undine Faction will result in the following:
Klinks and Feds can end their war.
We Undine looneys can start our war againts the feds,klinks and any other player factions.
Extreme Undine Chees nights (need 32 volunteers)