Does anyone remember some press about a shortage of seats to LAS? Your difficulty in finding a convenient/desirable itinerary is evidence. I think National Airlines will be coming to PHL later this year, too.

On another note, I will be flying HP SAN-PHX-ORD/MSP-PHX-SAN next week. How likely are upgrades for a CO gold on these routes?

PHX-ORD: A320, Wednesday afternoon
MSP-PHX: 737, Sunday afternoon