Troll topic if there one and asking for 50mm where we already have FA50, DA50, DFA50, FA43, DA*55 in the range... 5 lenses to cover the focal length are not enough? The DFA50 isn't sharp enough for you? The FA43 isn't small enough and doesn't offer a different enough rendering, DA50 isn't cheap enough? DA*55 isn't up to snuff for portrait? Come on.
I agree that some new lenses would be welcome, and I'am sure they will come. After all recently we got 16-85, 20-40, 24-70, 15-30, 55-300, 70-200, 150-450. That's far from bad, and from roadmap we are going to get quite a few interresting primes this year. No need to worry.
And it would make sense to concentrate where there potential hole in the lineup anyway then... On prime that could something around 24mm and large apperture, something for portraiture in the 85-135mm range... In zooms that could be a 24-105 f/4 transtandard or an affordable FF tele zoom like a 70-300.
Anyway, this isn't like we can't make great photos with what we have already...
DA55-300
F135
FA77 limited
DA35 limited
FA31
DA21
DA15 limited