I agree that a CO-HP combination is not likely... but I also don't see CO moving into DEN. For one, there's no incentive for them to do so other than being nice to the good people of Denver. IAH -- especially with the new expansion (and FIS expansion) can handle MEX just fine, and is a better xfer point for MEX-bound pax from all points in the USA than DEN would be.

As far as expanding a western route network, I got the impression that CO wasn't looking to expand its DOMESTIC capacity... at most, new destinations in the west feeding into IAH to new international routes would be a more likely move (courtesy of the 145XR).

If CO were to pick up a western hub, I'd like to see LAS before anything else. It's the fastest growing city in the USA, plenty of O/D traffic, lots of expansion room, and a great alternative for int'l connections than LAX. Because of the tourist traffic from aborad, I think CO has a better shot of sustaining a LAS base against WN/HP than it would a DEN or PHX base against WN/HP/F9.