While it isn't the most exciting, mind-blowing, game-changing addition to Dalaran thus far, I thought the addition of a cupcake vendor was pretty cool, especially now that they've itemized it. The vendor has some mundane found that are still pretty fun like Dalaran Brownies and Carrot Cupcakes, which are charming but not entirely what grabbed my attention.
What did grab my attention? She sells cakes! The Lovely Cake and Chocolate Celebration Cake are sold on this vendor, perhaps a little expensive (about 25g), but they work pretty neat. The cakes are used like Lightwells (Cakewell?), you lay them on the ground with a targeting circle and 5-10 of your friends can grab a slice. Maybe a Mage's food table was a better comparison, but I prefer the idea of a cakewell.