I think the one-menu limit of Hildon is a problem with the current Hildon spec. There needs to be a way to shoe-horn full functionality into a small form-factor. Toolbars also need to be more configurable; the whole toolbar-across-the-top (or bottom) concept makes some problematic assumptions about the screen size. I like the way gThumb auto-hides the toolbar in fullscreen mode (it can be recovered by tapping the top of the screen); I've found that this works well on the tablet...