it all depends on when and where you are jumping on the bandwagon (or not).
I jumped on the bandwagon with the X-E1 followed by the X-T1 when the first camera failed (long story) being repaired.
The idea was, for me, at the time: “ I’buy the more advanced type NOW, ...chances are that will be having a good performance for many years to come anyway"
Of course the X-T2 will show reasons to be an improvement over the X-T1 but if the improvement will be mostly limited to:
1) Pixel count
3) faster AF
Then I think that I will stick with my X-T1 and maybe I will even buy a X-E2 second body if and when the prices come down and the firmware would be brought at least, for the most part, at par with the X-T1 or 10.
Frankly I don’t anticipate anything “ revolutionary” ( by the way, I remember this film with Jean Reno , Leon, where he rays that a revolution means a 360 degrees turn which brings you where you were, while we all use this term as in "going forward! ") .
Chances are that most “ improvements" will be minor, revolutionary staying more or less where we are already, but the press, bloggers and rumor sites will all play it as the X-T2 will be the best invention after sliced bread ( is sliced bread really such an improvement?).
Until the X-T3 that is.