Just off the top of my head I know the Glass Cockpit and SLWT upgrades have a lot to do with it.

As far as the adapter goes, SpaceHab was working on a variant of their cargo bay modules that includes a docking port in the "ceiling" (nice little $100Mn contract for SPAB). Whether this is involved in the Ms. Morgan flight I have no idea.

IIRC, it was noted elsewhere that the Columbia can get to the ISS with a full-blown SpaceHab set-up. This was one of the key elements of the shuttle privatisation idea I floated earlier this year. Plus, apparently the Columbia is the only one ready-equipped for Extended Duration missions (got that from a NASA insider that was looking for reasons to shoot down a privatisation idea).

Cheers,
kadet ken