Pillow room: don't spend money on couches or lounge chairs and buy a really nice movie screen. (This would be really fun for movie night, to just move all the living room furniture and bring out the pillows!
Hanging baby bed :-) This would be a great thing to have. Whenever you had a newborn you could just hook it up next to your bed and take it down once the baby moves into another room. Great idea for trins swing