I haven't seen any official information yet, but if they do the same thing as last year, you will be able to use the Dining Plan for the CP Dinner package.
IIRC, it will be 1 TS credit since all of the participating EPCOT restaurants are 1 TS.
If you pay OOP for the CP dinner package, you get an appetizer in addition to the entree & dessert. I believe a non-alcoholic drink will be included, but not entirely sure.
Keep an eye on the boards for the official info. I'm sure it will be out before the 90 day windows open.