I don't believe that POET will only be in niches

GaAs can do EVERYTHING that Silicon can do Plus

Speed up the processing speed
Use Less energy
Combine Optical and Digital on ONE Chip
Reduce the cost of production
No retooling
Have all three memory types on one chip

So that means
One chip solutions for cell phones
Reduced number of chips in PC's
less recharging time
Smaller footprint for memory on board (all 3 types)
A LOT less r&d

AND
Quantum Computing in the future

I think that can take care of all the "niches" Don't you?