Although most of the DDP have no tip-included now, it did not change at the Castle or HDDR.
The tip is included on Castle meal. We were just there in May 2008. Everything is included at the castle meal...food, photo, tax & tip. And we were on the DDP, but we paid OOP for this one so as to use 2 TS at Cali Grille. When we booked the ADR in 2/2008, the CM did explain that the tip was still included at the Castle, but not at our other reservations. It is also included on the HDDR, though, according to the 2008 rules.
Here's the official wording from the 2008
Disney Dining Plan Brochure:
The Disney Dining Plan can be used for Character Dining experiences. One (1) Table Service meal for each person participating in the Character Dining experience will be redeemed from your meal plan balance, unless otherwise noted. Gratuities are not included.
Please Note: Two Table Service meals for each person dining at Cinderella’s Royal Table will be redeemed from your meal plan balance. Gratuities are included
Advance reservations are strongly recommended. Merchandise or photo imaging products that may be offered at Character Dining experiences are not included, except at Cinderella’s Royal Table. The Disney Dining Plan is unavailable for Guests under the age of 3…
The Disney Dining Plan can be used for Category 2 or Category 3 seating at all Dinner Shows (subject to availability) and Category 1 seating at the 9:30pm Hoop-Dee-Doo Musical Revue (subject to availabilty).
Dinner Show experiences include: Hoop-Dee-Doo Musical Revue, Mickey’s Backyard BBQ (seasonal), both located at Disney’s Fort Wilderness Resort & Campground, or Disney’s Spirit of Aloha Show at Disney’s Polynesian Resort.
Dinner Shows offer family-style dining with live entertainment show performances throughout the meal, themed to the Resort setting. Show tickets can be acquired through Concierge. All Dinner Shows require Advance Reservations. Gratuities are included
Two Table ❷ Service meals for each person dining at a Dinner Show will be redeemed from your meal plan balance.