Good point, Fairchij, reminding us that 40 nm could have been done in the lab! This is indeed another good reason to pick that size.
I agree that the fact that 40 nm PET can be produced on old equipment will be a major driver for POET, even without the optical and the integrational stuff. It enables POET's customers to directly compete with the most recent high-end products Intel, Samsung and GlobalFoundries are able to produce (TSMC to follow), i.e. 14 nm FinFET, but at a fraction of their costs.
This is really huge und underestimated!
And now what will happen when all the other POET goodies enter the game?