One of the main things that isn't open yet imo - is Breakfast at MK. Or California Grill Sunday Brunch.
Nor are any of the dinner shows open yet, or focused Character dining (1900 Park Fare, Royal Table, Akershus, Disney Princess Tea, Story Book Dining)
Alot of the big dining event places are not open yet - Boma, Jiko at AK, Victoria & Alberts, Monsier Paul, Tokyo Dining & Takumi-Tei in EP, Flying Fish, ESPN Club (may not come back), are not open yet.
And the food courts for resorts that are not open of course.
Other NEW restaurants that are supposed to open soon:
The Wave (re-themed/re-opening by Oct 1)
Space 220 (supposedly by Oct 1)
Woody's Round Up BBQ (supposedly by Oct 1)
California Grill Themed Dinner (Oct 2 on)