As a practical matter the mirrorless body with large lens vs. mirrorbox body with short lens argument hasn't changed consumer behavior in the APSc or FF markets, and it probably won't in the crop MF space either. People buy shiny things and ignore their obvious shortcomings as a matter of self-justification.
I've said many times Pentax is (or is forced to be) an alternative to CaNikon, not a true competitor with them. I've thought for about a year Fuji is Pentax's
real competition, and here we have an insurgent's strike, planned and developed while Pentax was busily bringing the (probable) final FF dSLR line in the industry. Ahem.
Was K-1 too little, too late - or does Ricoh have something bigger around the corner? My gut tells me there is a very large, very clever surprise coming from Pentax, and I don't mean a quick release battery grip