I doubt there will be any discs where the main feature film won't play, however with BD+ and advanced BD java they may take a very long time to load.
Some special features like picture in picture will never work on the BD-P1000, but you're in good company as there are no stand alone blu-ray players on the market yet (at least I don't think there is a 1.1 player out yet) that will do PIP.
Doug
Edit: I forgot that the menus on The Day After Tomorrow kind of work. For instance you can press play and it will play the movie. However if you goto the scene selection, select a scene and click on it, it will make a noise and the icon will light up, but nothing happens.