After the last restructuring, I said
Remember, US Airways sold 10 Embraer 190s and now, the remaining 15 will fly only Boston-LaGuardia on the Shuttle and Boston-Philly. That means they'll need some other narrowbodies to fill in for those airplanes, so things will just cascade down. It wouldn't surprise me to see some 767 flying in the Caribbean, though I don't know for sure.Sure enough, things are cascading down. US Airways says it will operate this route with a 757 configured with 12 first class and 164 coach seats. As Dan Webb notes, this configuration only exists on their internationally-equipped 757 fleet.
Many of the European destinations losing service were served by 757s, so US Airways now has to look for opportunities to use those airplanes elsewhere. Anchorage is a market that only works well in the summer for most carriers, but you don't see flights from the northeast. Even Continental fails to link Newark with Anchorage. Its flight stops in Seattle.
So will this work? My guess is that US Airways wouldn't be ordering new planes to run this route, but they see the opportunity to test it since those airplanes don't have better uses this summer. It might work or it might not, but it's worth a shot.