Forget it. DVD uses a VERY limited technology to draw subpictures. Creating an animated subpicture would not only be extremely difficult and probably ugly, but would create such a lag in interactivity that it would break many set-top and desktop players. Your best bet is to focus on good design and good anti-aliasing for your static subpictures. Now, that's not to say you're prohibited from making awesome looking motion menu loops with animated indicators that use STATIC subpictures as buttons...
It would be possible by defining animated transition clips and using auto-action with invisible buttons, but you would need a transition clip for every button plus multiple menus to reflect the states, so managing it all becomes a lot more work. And what TimeRemapper said is true - it will lag awfully and slow down things. In fact if this is for a portfolio DVD, it may annoy the people watching it and have the adverse effect - anything that can't be said in a single clip with auto-play is probably not worth watching.
Unless your specialty is creating DVD menus I'd keep it very simple. For several years I was in the position of hiring new people for a television station and for more years than that I was on a hiring committee. I can tell you that we knew if we were going to hire someone based on the first 30 seconds of their reel. It's fine to include full length pieces in an audition reel, but don't expect anyone to watch them.