It looks like Mozilla's following the path Opera blazed and will be submitting their own app, Firefox Home in the no-too-distant future.  Although pages are still rendered using Mobile Safari, Firefox Home will allow you to access all your desktop Firefox bookmarks, open browser tabs, and full access to the "Awesome Bar" Firefox is known for.  The fact that they'll continue to use Mobile Safari for rendering certainly makes it likely we'll see the app approved when Apple gets around to it.