if your kids like the Disney store, they will love love LOVE the shops in DLP! While IMO the shops used to be more themed (anyone remember the bazaar when it had really unique stuff like metal boxes and leather slippers and stuff?), now you'll find some of the shops do sell the same things, but there is differentiation between them. The shops are as fantastically themed as the rest of the park, so get your kids to notice these details (for example the shop windows in Main Street USA are always eye catching, i think the theme this year is over the rooftops of paris?)
They'll love it, and more to the point - so will you!
Lucky kids. The shops are fantastic. I alway go saying what else Disney could I possibly need - it lulls DH into a false sense of security . My case is always full .
BTW - you can get some really nice luggage bags at the hotel shop.
Letting the kids take their birthday money last year meant I had to go and buy a very large holdall for the return journey.