Apparently iMovie is indeed only compatible with iPad 2. It isn't available on the app store when I'm on my iPad 1, but Garage Band is available and I'm downloading now (VERY slow download, servers must be overloaded).
Welcome to the Apple iPad Forum, your one stop source for all things iPad. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!