For customer service, after-listing editing, or inventory issues we will often need to search SKU's for several items to open the listing and having either a fixed search bar in the control pane or a hover/drop-down option (like the "Drafts" pop-out under the Items menu) would be very useful. Right now if you open the Edit page you have to either save and back out a couple of steps or save and click back into the PRODUCTS page to search for the next item.