PanasonicVac
Oh, well that seems a bit more reasonable... but not by much. That's like if Coke were to sue Pepsi for selling cola flavored pop. Sure, they're both the same type of pop, but they're different in their own respects. As long as Ryobi wasn't copy+pasting the Elite design and using the same bags and belts, I don't really see the problem.
At least that makes obtaining parts a bit easier in case I ever get one ;P