Apple made a tiny change to the way the Dock works in Mountain Lion that’s causing a lot of aggravation. YES, you can still remove shortcuts from the dock (as long as they’re not currently running). You just have to drag the item a little farther away than before –a couple of inches– and wait one second for the “poof” icon to appear. Now you can let go of your mouse and the item will be removed. As always, items in the dock are just shortcuts, the original still lives somewhere on your system.