These articles are a week or two old, but the additional train service finally started a week ago. I went onto the Amtrak Cascades site and calculated the cost of a round trip on the train from Vancouver, BC to Seattle.
The new morning train out of Vancouver leaves at 6:40am and costs US$35 for that leg. It arrives in Seattle at 11:00am. Four hours may seem long for those who are used to speeding down I-5 to the outlet mall or elsewhere, but it’s a nice stress free way to enjoy the trip. However, I have heard that Amtrak has tons of delays everyday.
The evening train leaves Seattle at 6:50pm and arrives back in Vancouver at 10:45pm for a cost of US$35. So if you wanted to do a very short day trip in Downtown Seattle, you could now. I think it would feel a little too rushed, though. I would love to go overnight and catch a Mariner’s game in the evening and return the next day in the evening instead. For US$70, I think it would be worth it. I wouldn’t have to think about driving or parking.