In the 5th edition rulebook I noticed a comment about the niccassar on page 117 about the Thexian empire "Hailing from the oxidized worlds known as the Bloodmoons, the Thexian Elite are a Bimorphic race few in number but strong in influence. They are masters of manipulation and have worked themselves into integral positions in the Borlac, Loxatl, and Nicassar civilizations. Though Thexians are famously persuasive, when guile is not enough their battle form is quite horrifying to behold."
Now from what I understand the Nicassar are part of the Tau empire, as it states it seems that the majority of it has found itself subject to Tau rule, if not all. Also Nicassar travel in slow ships, albeit great distances, the ghoul stars are a long way from the tau empire. Now this could prove several possible conclusions, of course that the Nicassar are a very old civilization and have travelled a distance of at least halfway across the galaxy in their sublight ships, and/or That their point of origin is not very close to the Tau empire. Or the Thexians are widespread throughout the galaxy, possibly in pockets at the furthest borders of the imperium much like the Phonecians were.
I find the possibility of some follow up of this interesting from
GW, perhaps there are different 'sects' of the Nicassar, parts of their community being controlled by different entities. We might even find a different kind of Nicassar under control of the Thex than those controlled by the Tau. Seems like a possible tie-in for a new 40k army, although we probably wouldn't see it till shortly before 6th edition in about 4 years, much like chaos daemons.
Anyways I would like to hear peoples thoughts on the subject.