In addition to the capital CO would need to commit to a DEN hub, there will inevitably be a fare war between CO and UA. And I have the feeling it will be bitter, vicious and far more extensive than the UA/WN campaign. At least WN was not threatening United's international routes.

While it's more west than anything else CO currently has it's not "west" enough. For the same reason that everyone still stays in the crowded NE corridor airspace if you want a western hub you'll have to put it on the west coast. That's where the people are and that's where the money is.

Also, without more planes where will CO pull service to accomodate a new hub? With the inevitable 787 delays and unless they're hiding plans to acquire many new widebodies the existing fleet is already stretched pretty thin between the new PVG and LHR slots.

As for would I fly them out of DEN? Sure, if the fare was cheap and the timing worked. Based out of BOS, I'll connect in IAH if I want the miles and in EWR if the fare is cheaper (usually is) and I can add in enough time to account for the need to switch terminals plus ATC delays.