Anyone who thinks Lucas is a hack should look into technologies like EditDroid, Skywalker Sound, Industrial Light & Magic, THX, the new Sony digital camera and look at the effect they have had on the industry. Over the past few decades all of these things have revolutionized every single aspect of the medium. Movies simply are not made the same way they were thirty years ago, and I think Lucas deserves credit for that, if for nothing else. Films like Jurassic Park, Titanic, or the Lord of the Rings would not have been possible without the work he's done.
Best director? Certainly not. I think Episodes I and II were failed experiments (Episode III remains to be seen). Bad movies? No way. You wanna see a bad movie, rent "Glitter" with Mariah Carey.
The point is, Lucas tried to re-invent the way movies are made (again) and he took a completely different approach to making a movie than anyone had before. Some of it worked brilliantly. A lot of it didn't. It's "avant garde" art in the worst sense. That doesn't mean digital filmmaking is bad. The important thing is, the work he has done will carry over to contemporary and future filmmakers and they will study his method and improve on it.
How does anyone know what will work unless there are people like Lucas who dare to push the envelope and try new things? Otherwise we'd all be confined to watching the same movies over and over again. How many times can you watch crap like "You Got Served" before your eyes start to bleed?
Believe me, history will look favorably on George Lucas. When people take a step back and look at all the things he's given us during his career - Star Wars, Indiana Jones, Howard the Duck... er, okay... Maybe not Howard the Duck - they will see that this man's contributions were valuable to our culture, and that the world was a better place because he lived.