I was on the MouseSavers sight and found some info on the additions of snacks.
What Can You Get With Snack Credits?
As of May 2006, Disney has expanded the items available with Dining Plan snack credits. Disney is now generally defining a “snack” on the Disney Dining Plan be an item under $4 (pre-tax), edible, non-alcoholic, non-merchandise and non-souvenir. Some items such as pizza slices are excluded.
Snacks can be redeemed at quick service or snack cart locations only. Quick-service and snack cart locations display a “dining plan” logo on their menus indicating items for which you can use your snack credits.
Among the items now available with Dining Plan snack credits:
ice cream novelty
frozen fruit bar
box of popcorn
12 oz soft drink
20 oz Powerade
24 oz bottle of water
piece of fruit
bottled fruit juice
snack-sized bag of chips
ice cream sundaes
ice cream floats
Mickey rice krispy treats
Also, during the 2005 Food & Wine Festival, snack credits could be redeemed for most “tasting portions” offered in the booths around World Showcase. Hopefully that will also be true in 2006.