Not official yet but Mercury was allowing some journalists to ride in new 4.5 and 4.8 four strokes from 300 to 450 horsepower is the rumor I heard on another forum. They are V8's.
I heard the several of the lower horsepower Verado is going away so they can sell the new motors. I am guessing but did not hear that they will get rid of the higher horsepower Verado after these larger blocked motors come out. The Verado has been a 2 star CARB motor and I'm guessing that may be the reason.
Also a guess but the larger 2 strokes days may be numbered. Mercury said they will probably come out with these next year.