Realistically, Pentax has known about this sensor for at least one year.
The lack of EFC was IMHO the only remaining significant isssue with the 645Z, so the 645X (whatever it's called), should be perfect for people looking for an integrated solution.
It should be very clear at Pentax what they need to do lenswise and odds are that these designs are pretty advanced already. If I were them I would publish a clear roadmap together with the next body announcement.
Cheers,
Bernard