In IM 3, I was able to right-click and copy the cache image from the viewer window to the clipboard, but I don't see any way to do this in IM5. The viewer has clipboard options, but they are grayed out. If I want a quick copy for an email or something else, I have to open the image in Photoshop and resize it or run a script) which is not as fast as just making a quick copy. There is no option to copy either from the Quick View or the Viewer window.
Not a must-have feature, but often helpful.
Added for 5.0.108.
Available as Copy Image in the File Window and the Viewer context menus (<Ctrl>+<C> , <I>)