The diameter of a wafer determines how may microprocessors can be made from it. The larger the diameter the more that can be made. The factories that make these use different sizes but the importance of 8 inches is that it is a very common diameter for production in factories. Previously they were made on 6 inch wafers but the change was arranged to make it both more productive and to match a common size used in various manufacterers' outputs. It means that POET microprocessors will be easier to mass produce when contracts are signed. So yes it does have commercial implications and 8 inch wafers fit best.

David