Passport 20 approaching freeze!

See:
http://www.flightglobal.com/news/articles/ge-aviation-prepares-to-freeze-passport-20-engine-design-371102/

Passport 20 shall be frozen by the end of this month next Monday.
It shall be in service on Global 7000 in 2016.

On entry into service, Global 7000 shall be the biggest and heaviest GA plane which is not a private version of any airliner – bigger than Gulfstream 650.

What is the dividing line between Part 91 and Part 125 operations?