Only other thing to think about is if you want to get the stuff off your nano.
iTunes is a one-way sync, copying music from iTunes from nano.
If you want to keep the music on your nano (and old laptop), you need to copy this music into iTunes first, then sync the nano. It's easiest if you copy from laptop to laptop, but if you can' do that, you can use something like yamipod (Google it), to copy from nano to iTunes.