Cycle World tested the SMR450 in the April 2007 issue. It put out 48.3 hp at 8,500 rpm and top speed was measured at 106 mph.
In physics terms, 106 mph is an awful lot faster than the 95 mph people are claiming for the WR250R. Wind resistance increases with the square of the speed and all that. I see no reason to doubt that the WR250R will honestly exceed 90 mph.