Sigma and Zeiss to a lesser extent have upset the status quo as to what is expected sharpness wise from the fast prime. One could argue that part of the fun and flexibility of using a fast prime was the softening of the frame the further you moved from center when used @ f/2.8 or wider.
So if you take it as said that photographers want more sharpness across the whole frame the the FA*85, FA50 and FA24* would need a complete rethink from a design perspective. I have omitted the 43 and 77 because I think that these are regarded as specialist lenses like the A50 f/1.2 and will be treated as such. Pentax are rightly from a business perspective focusing more on the zoom range as the majority of potential new customers will demand these optics. The road map suggests a range from 15-450 with a mix of high end, prosumer (mid range) and probably a couple of consumer (kit) zooms to get started with. This new range is more targeted at experienced / demanding photographers from the off with the 2 pro staples of 24-70 f/2.8 and 70-200 f/2.8 getting Star or Professional status. Birders and wildlife are covered by the 150-450 which has been demanded for years by the American / European community. Budget over €6,000 for these 3 optics
Getting back to the primes, 20 something is a gap that is screaming for an optic, be it D-FA Limited or D-FA *, the 35 and 50 in DA and FA formats will soldier on for another couple of years but if Ricoh has design resource capacity I would hope that they re-release with body's similar to the 100 macro and update the coatings. Sexy
alloy bodies, HD coatings, WR, DC motor technology and keep price at under €399 and you could have a good revenue stream from new recruits and updaters alike. 50 macro, and I have been saying this for years needs a new body. Give it DC and WR and it will quietly look after itself until the end of the decade. It is a fabulous optic, ignored and shunned for years rarely getting the plaudits it deserves. But all new prime designs? Late 2016