There is now a Plastics Workbench update on the Perrys website, post Salute.
Pure speculation but, we know that the Afrika Korps will be next set (around June 13?).
I would assume that either the ACW artillery (guns and limbers frames are already tooled) or AWI maybe next - partly as Alan tends to sculpt faster and maybe that it's his 'turn' to release a plastics set (..am sure they really don't plan on that basis, by the way!!)? These could be Sept/Oct 13.
Therefore....we
could just be looking at one of the late medieval boxes by end of year?? A Christmas present to look forward to perhaps...

...now which one of them would it be...?
Musing is great, isn't it...

Cheers
Simon.