If you havent purchased the 5n yet, I'd hold off if I were you.
Sony is bringing in the 2012 models soon.
The replacement to the nex C3 has already arrived as the Nex F3 with a 16mp sensor.
One could assume that a new Nex 5 series camera is around the corner as the F5
Even though they really haven't acknowledged the overheating issues of the 7 and 5n, its there, so maybe a refresh will be announced later this year.
sonyalpharumors.com has some tidbits and speculation.