The upgrade question is anyone's guess. The short answer is if SWA never again grows, then upgrades will be in the 20+ yr range, since we have a relatively young pilot group (soon to be made even younger if the ATN captains get to keep their seats). However, the idea of no more growth at the country's largest domestic carrier (who has yet to even scratch the surface of any international ops) is a bet I'd be unwilling to take. SWA has long built their reputation on Wall St. as a growth stock (and company), and if the industry can finally get beyond terrorist events, high oil prices, and the current antiquated ATC system, then I believe you will see that growth return again.