You can navigate to the parts of the page not shown on the screen using the new onscreen arrow buttons. If you select "Fit to Page" from the View menu that displays the entire page. Immediately after selecting that option it gives you garbage on the screen but if you hit page forward and then page backward it displays properly.

Also, you can't annotate while in landscape (and any annotations you made in portrait mode vanish until you switch back). You can highlight though.