KING-TV, Channel 5 in Seattle, WA, 1/22/18:
WSDOT looks into high-speed train from Spokane to Seattle
The Washington Department of Transportation is looking into how a high-speed train from Spokane to Seattle would work.
The story is here. There has to be some skepticism here, as it is in no way high speed. Maybe higher speed, but even with the Stampede Pass route instead of the current Empire Builder route, I don't think it's possible to maintain 90 mph along the entire route. I would expect conventional trains and speeds. Just improving the frequency of trains beyond the current ONE between Spokane and Seattle is itself a big improvement, especially given the current calling times in Spokane.