Summer of 2008 Portlanders will be able to take the train up to Vancouver, BC without having to stop overnight in Seattle (and vice versa). At least that’s what this article seems to be saying:
When the new service begins operations, Amtrak Cascades will depart from Vancouver, B.C. in the morning, travel to Seattle, and then continue on to Portland, Ore. Each afternoon, another train will depart Portland, travel to Seattle, and then continue on to Vancouver, B.C. This service will supplement the existing train that makes a round trip between Seattle and Vancouver, B.C., departing Seattle in the morning.
I’m planning my trip already!