You may be confusing the DDE (Disney Dining Experience) and DDP (Disney Dining Plan).
The included gratuity has indeed been removed from the Disney Dining Plan for 2008. However, no automatic gratutity will be assessed for your Dining Plan order unless your party consists of 6 or more persons. According to the 2008 DDP brochure, you may be charged a gratuity for off-plan items that you order separately (like alcoholic beverages).
The Disney Dining Experience (DDE) is a discount program for annual passholders and Florida residents. This is the program that will have an automatic gratuity added regardless of party size. And since DDE members don't identify themselves as DDE members until after the meal is finished and they're ready to pay, it may not affect service. We'll have to see what happens in '08.
There's an exensive thread running on the Restaurants board right now about the automatic gratuity for DDE members.