Feature Episode series are, in my opinion, the single most vital element of Star Trek Online. We've waited far too long for the fourth series, and I sincerely hope that a great many will follow.
They are what kept me playing back at the beginning of 2011 when I started to get bored with the game. And the lack of them kept me from playing most of the summer! I agree, it's been WAY TOO LONG! I remember reading somewhere way back that they would be much more frequent...then again I also remember reading somewhere about a new Enterprise and new content back before all this F2P nonsense. Oh, to long for the glory days of STO this time last year.