...but DTD at WDW is just a boatload of the same ole, same ole crappola. What is the appeal and how is Disney maintaining the crowds?
Other than World of Disney, that's really not true. Sure there is the pin stand, toy store, sports store and others which carry a lot of Disney stuff but if you're looking for something in particular--or want the best selection--much easier to go to DTD rather than scouring MouseGear, Emporium, etc.
There are also dozens of unique shops and restaurants. It's not just T-Rex and Planet Hollywood--there are some decent restaurants.
LEGO store, Cirque, Ridemakerz, DisneyQuest, Basin, Little Miss Matched. D Street is apparently popular among those who collect Vinylmation.
WDW has added street musicians reminiscent of DL. Improved the atmosphere.
Maybe not your thing but there is much to do at DTD that Middle America doesn't have a block away from their homes.
I don't go to DTD as much as I used to. Ironically the main reason is because every time I visit, it's even more crowded than the last. 3-4 years ago when my son was big into LEGOs, I could always find a parking spot in the lot immediately adjacent to the LEGO store. That's right around the area where the Marketplace and PI meet.
Last three times I've been there (spread over 2010 and 2011) I had to park all the way down in the West Side lot EVERY TIME. One was an afternoon visit and two were very early evening (4-5pm) on a weekday and the lots were jam packed. I don't even go into World of Disney anymore because it's literally elbow-to-elbow.
I'm well aware that many folks miss the AC and prefer City Walk, but by all appearances DTD as busy as it's ever been.