Let's speculate: In the near future, Seattle decides to give all of its port business on Harbor Island to Tacoma, which has a port that, for many years, rivaled Seattle's (the two joined forces recently). Once liberated from the real world of labor and industry and working-class jobs, Seattle transforms the old artificial island into something to do with luxury (luxurious living or consumption, or both). This will be seen as a win-win kind of thing. Tacoma get's the jobs and economic realism it desperately needs, and Seattle's developers get a chunk of property with spectacular views of the bay and downtown. Seattle continues down its royal road to Manhattan ("one vast gated community for the rich"); and Tacoma continues to keep it real and gritty.
Two stories inspired this brief blast of speculation. One, "The Seattle-Tacoma economic divide persists," is by Seattle Times columnist Jon Talton. The other is a KOMO report, "New shipping alliances jam up truck traffic for Port of Seattle." The former points out that Seattle and its King County is much richer than Tacoma and its Pierce County, and believes this disparity is as old as the cities. The latter is about the worsening truck traffic in Harbor Island. More and more trucks are waiting for longer and longer stretches of time for their assignments from around the world. This traffic is now generating "complaints around the port." A bicycle commuter, Patrick Lathrop, to KOMO: "What's really bad is when they are lined up on East Marginal (Way)... You breathe the heavy diesel fumes and that just gets obnoxious."
Put those two stories together while keeping in mind the current housing bubble, a big part of which is inflated by high-end developments, and the door opens wide for this kind of speculation.