Since the new 2 strokes are meeting the 2006 emission requirements, I bet the 2 stroke will stay, and the emission limitation (2006 spec engine) will be the requirement for the waters. I have a 4 stroke on a smaller boat (16' Arima) and weight is the problem. Boat rated for 100 HP, but the 90 HP 4 strokes are so heavy in the stern. You can get 90's (2 stk) that are 100 Lbs lighter, and cheaper. The Evinrude site shows the 2 stk 'Rude to be cleaner then the corresponding Yammie 4 stroke and getting as good or better economy. I do like the quiet Suzie on my boat, but the kicker (Yammie F8 4 stk, lightest one I could find) has twice the hours on it in just 10 months use.