Actually, various people claim that Ogg infringes on their patents, so I wouldn't say it's out of the woods yet. It's still a perceptual audio coder, and Frauhofer/Thompson hold a lot of patents in that area. I'd be very suprised if Ogg didn't infringe at least one of them - not to say they didn't come up with the ideas themselves, just that it may well have been patented before that point.

Hugo