Cute and no rolling diapers! - I love the square cake idea, it's much easier and smarter! I'd use different colors and more decorations but I've never seen the diaper cake in square form before, and I absolutely love it!
"Hospital survival kit for new mothers" - little things that may come in handy, but may be overlooked when packing the hospital bag. Baby shower idea (if close enough to the due date that the food is still good!