Never a good sign.
It's never good to hear, but it's true - TERA is merging many of their servers into one, creating three server subtypes. One for PVP, one for PVE, and one for roleplaying. The announcement came from a producer's letter to the public which you can find here (although it's currently down, probably due to floods of shocked TERA players).
Their new FAQ details all the information, including which servers are to be merged and what happens to all the content therein.
Julian "Mirai" Williams