Karen--The HISTA (Honey I Shrunk the Audience) 3D movie is in Epcot. The playground is in MGM.
The playground is a wonderful place for a 1 year old. There are all sorts of oversized plants and toys for kids to climb on, slides to go down. My kids loved it at that age and still do! There are some areas a 1 year old can't venture into, but still plenty for her to do and a nice change from sitting in the stroller, etc. My youngest couldn't walk at 12 months, but still managed to enjoy the playground there.
The HISTA movie, on the other hand, is a big NO for very young children. My 8 year old niece freaked out during the movie and was scared of any dark rides for the rest of the trip. There are other 3D movies she can enjoy--Muppetvision at MGM and the new Mickey's Philarmagic at MK. Do be careful with the 3D glasses though. My 2 year old stuck the end of the glasses up his nose and his face was covered with blood when we got out of Muppetvision. He didn't cry or anything, but he looked like he was an extra on a horror movie set. You can watch the movie fine without the glasses. It's just a little blurry in spots.