Of course, the best way for a Flyertalker to do her Christmas shopping is on the internet, via one of the portals (like Marriott's) that gives you points for $ spent if you click through their portal on the way to another internet retail site
But that's not exactly festive ...
What about a location that has a decent premium outlet mall that is also near an interesting city? I'm not sure if it's any good, but the Petaluma Premium Outlet mall combined with a trip to San Francisco might be a possibility. (Of course, if you go to New York, you could do Woodbury Common + NYC shopping.)