www.watchprosite.com
In summary, we have no idea 
But it does seem no more names are being added to waiting lists now (but also perhaps the waiting lists were nearly cleared, maybe after PP made the last batch and decided it was after all a rather 'difficult' watch to make then time to have a rest - this is pure speculation on my part).
However this is a completely new and so far unique calibre, surely they have some more plans for it?
Whilst the watch is a litle love/hate I think most love it and especially the dial (which I think is the subject of some of the production difficulties)...