The latest generation of iPods work on both platforms without a hitch. You don't need to worry about it.
Just plug it in, and it works! (If you have a firewire or USB port). The only thing you would want to be concerned about is if both computers were configured to manage your songs through their playlists (in that case each sync would remove the other's songs).
But that makes me wonder, would the iPod work via VPC and the USB port?