For the kids room instead of replacing the broken tracks? Create more space in the bedrooms by removing closet doors and replacing them with curtains. Furniture can now be placed closer to the closet since you no longer need room to open the doors.
girls room idea for hanging storage and bookcase with curtains. frame off bookshelf and top with crown molding, add curtains on a rod to hid the mess when you need too. Also diggin' those rolling pin hooks, heehee.