733 replacement is not even tabled to be examined untill 2010, know that saying don't f**k with what works? Yeah well...
Highly unlikely that airbus is an option.
Q400? Stop smoking that stuff cuz random drug testing is now in the workplace.
My bet is that the smaller cousin of the 787 is what you will see operating the domestic network come 2012-13
The A320 is not popular on the domestic network as the Cargo cans are to slow to load...