I really didn't see much difference. Mainly it was in the food/drink options in the existing restaurants. Sometimes a special souvenir. It definitely wasn't like EPCOT with the food stalls, etc. Although I was only there for a few days, so maybe later on they add more stuff?
It's basically just a bunch of temporary menu items at the snack stands around American Waterfront and the restaurants. There's also a few souvenir items you can buy. There's no additional food stalls put up or anything.
There's also some lectures about food on some days in June but they're only in Japanese and you have to reserve them in advance.
I didn't particularly like any of the food and wine festival items I had last year so I'm actually planning to skip it entirely this year and only go to Disneyland this season.