If this is true (which I won't belive until I see that 50mm 1.0) it is great news!
I'm with RiceHigh on this one, but I think FF lenses would should only come back for two reason: recycling old lens designs to save money, or planing for a FF body. DFA* 20mm F2.8 SDM could be in the first category, DFA* 50mm F1.0 SDM is for sure completely new to Pentax so that would mean FF body in planing. Finally!
If Pentax feel they have the resources to make a FF body it's about time they did so. IMO they are bound to do so sooner or later if they want to be in the game with the big players.
When they have put out the FF DSLR and 645D they can start planing the 67D, now wouldn't that be something