We'll be there too! Been there every Memorial Day weekend for five years.
One word of advice - don't expect to get into the Tatoonine gift shop without a bit of a hassle. It's too small and too crowded. If you absolutely have to have some merchandise, be prepared for a wait to actually enter the shop (unless you are coming from the attraction and then it's slow going) and then mobs of people in the store.
Also, the handler for Queen Amadala last year was a real pill. She didn't even want me to take a picture from well across the autograph line. Most of the characters will be out and there are photo ops from decent distances. The area around Star Tours is like a party. There will be other Star Wars characters over on Mickey Avenue as well. All in all, a very pleasant way to spend the day.
And don't forget to look up as you enter MGM. There are certain people up there to "greet" you.