By all indications and official posts by kupa, most of the features of the P4 Pro Pack will be a part of Poser 5, including multi-paned windows, the figure setup room, animated materials, and motion blur. I assume that P5 will stick with PNG thumbnails; I see no reason for the format to be changed again, since it works so well. I don't know about the plugin support for third-party applications like Vue, Cinema 4D, and so on. Guess we'll find out tomorrow.