My DH and I sold our house a couple of years ago. I'm also a real estate broker, so I've been on both sides of the fence. My advice is to definitely pack it all up. Get rid of as much clutter as possible. You may want to keep one project aside, so that you can work on it and then easily stash it away when people come to view the house, but other than that...put it away. You want that room to look nice and large, as well as clean and inviting. You'd think that people can imagine it "clean and tidy," but you'd be amazed at how many people can't. It may make a big difference in your offer price. Good luck!
~ C