Since there was some interest, I'll go ahead and post a few restaurant suggestions for those who are spending any time off the ship in Galveston. There are a few close (walking distance) places to the cruise terminal. Since you're on the water or on the "Strand" there, you're paying a slight premium for the food. (The Historic Strand is one of the nice, old parts of town that is restored, and is mostly now shops and restaurants. The cruise terminals are basically next to it.)
If you have kids (or even if you don't) La King's Confectionery is worth a stop. (They're on the Strand, basically a block and a half walk from the cruise terminal.) They make a lot of their own candy, they make their own ice cream, and the building is more than a century old, as is some of their equipment. They're a soda fountain and candy shop, and if you've never been, you really should consider it. It was my favorite place in Galveston when I was a child.
Along the waterfront on the harborside (down from the cruise terminals, where you can actually sit and watch the ships head out) are a handful of reasonable options. Olympia Grill has pretty good Greek food. (I actually like the food a little better at their original location, on the other side of the island, but the views and convenience of this spot make up for it.) There are a couple of competent (but a bit overpriced) seafood restaurants there, too. Willie G's is a little more upscale, Fisherman's Wharf is larger and has great views throughout the restaurant, and, IMHO, slightly less good food.
If you want to branch out a little from the Harborside/Strand area, the Original Mexican Cafe has decent Tex-Mex, with some seafood on the menu, since it is Galveston. It's fairly close, but you'd want to drive there, not walk.
If you want to eat where the locals grab their seafood, try the seafood po'boys at Shrimp n Stuff. They're reasonably priced and tasty. (I actually had a shrimp po boy there yesterday when we went down to Galveston for the day. With extra tartar sauce. And an order of the spicy hush puppies.) They are not quite as easy to find, being on a side street, but they aren't too far, maybe 10 minutes from the harbor area.
Rudy and Paco's and Mosquito Cafe are also generally good, and offer more "foodie" food, with pretty interesting menus and good quality ingredients. Gaido's (a seafood house on the other side of the island from the terminals) is famous, but it hasn't been as good the last few times I've been there. Honestly, I wouldn't make the drive to it right now.
Oh, and my mother would never forgive me if I didn't point out that there is also a Starbuck's basically across the street from the cruise terminal. (It's across from the terminal Carnival uses and down a little from the one that Royal Caribbean uses. It occurs to me that I'm not sure which terminal
DCL will use.)
That covers a lot of styles of food, at several different price points. Of course, none of us may be hungry after a week on a cruise ship... ;-)
A wedding on the Disney Magic with the Magic of Disney all around you does sound very speciall!
) and right now they are finishing up a Pleasure Pier that should be open by the time of the cruise, that will have rides and I'm sure food, considering it is a Tilman Fertitta project (the Landry's group, who also owns Rainforest Cafe). I believe the headline restaurant at the Pleasure Pier is going to be Bubba Gump Shrimp. We drove by the (repurposed, it used to have a hotel on it long ago) pier Tuesday, and you could see a roller coaster and a ferris wheel rising high over the ocean. It looked like it would be fun and a big tourist draw. Probably not insanely crowded by November. 
Guess I will just have to get on here and plot to satisfy my planning urge!
