It would be awesome if we could have a metro 1/3 screen app on our desktop, that auto-hides like the windows taskbar can...

The only problem i see would be the fact that it resizes the desktop, so you may have to make it less sensitive (either make a hotkey toggle hide state, and/or make a mouse gesture, i would recommend moving mouse to bottom right corner, and dragging it upward along the edge, this conflicts with the search bar, but the searchbar also works with the top corner.. so i dont see a problem replacing it..