I read an article not 2 months ago in which CFM said they could equip a 737 with an engine that had a moderately larger fan than the current CFM56 engines but have less blades (so weight penalty would be minimal) but as the blades would be of new technology, the engine would have the same 1:10 bypass ratio as the model of the same engine that will likely be strapped to the A320NEO.

In other words, they can supply a potential 737 “NEO” with the same engine as the A320NEO and it will enjoy the same bypass ratio and similar fuel burn improvements.