The question is(or are):

which sensor?
Apparently(rumours) Canon is considering using a new 50ish Mp Sony sensor on one of their new 5D replacements.
Do Pentax go with what's already out there(is. 24 or 36Mp) or do they go straight for the super high res jugular?

I think this explains the lack of a name and firm release date.
Maybe they're planning two versions!
A high resolution 50Mp version and a low resolution 36Mp version too