Portland will get a team if and when Paul Allen decides he wants another toy. He owns the Trailblazers and controls the arena (Rose Garden).
I still think Vegas is the best untapped market. No professional sports (unless you count UNLV) they know how to market, they have a growing local population, and a huge tourist influx every day.
Now, the question is can the league get over the obvious gambling connections. I don't think the Canadian teams will have a problem with it - isn't there a legal sportsbook type lottery in some provinces? Convincing the US owners is another story. It certainly would not have been picked as an expansion market, but if an owner tried to move there, how much would the league oppose or try to stop it, especially if the alternative was threat of bankrupcy/contraction.
But did I mention - Vegas knows how to market. Can't you just see the glitz, Fire and Ice, Ice in the desert, Vegas on the Rocks, etc.
But outside of Paul Allen, Vegas is the only real appealing relocation market.