Portland's not losing their team...yet.
But the writing's on the wall; we already saw Calgary try with Abbotsford BC, and both Dallas and Carolina have moved their teams (Texas Stars and Charlotte Checkers respectively, from Iowa and Albany) closer to home with moderate success. Philadelphia's baby Flyers are back in Eastern PA after being in Philly before losing the Spectrum, too.
Arizona, Colorado, and Vancouver won't wait long to pull their teams (Portland, Lake Erie/Cleveland, Utica) out west to match. Winnipeg won't keep the IceCaps in tiny St. John's forever; Tampa and Florida both have ECHL teams they can elevate nearby (Orlando for the Lightning, and the Florida Everblades for the Panthers); Springfield is on borrowed time, and Columbus will jump to fill in Cleveland if the Avalanche vacates it.
If the Islanders do what is expected and pull the Sound Tigers to Nassau, the Rangers will jump right on Bridgeport with the Wolf Pack struggling to draw (and with the persistent arena problem). The Habs have been preparing to pull the Hamilton Bulldogs into the Montreal suburbs. Binghamton lives or dies according to the goodwill of the Senators, because now both of the prominent Eastern Canadian franchises will have brought their teams into their home cities.
I give it about five years or so before the AHL pretty much looks like the NHL, in smaller cities.