Ipod sync'd to old library after reformart/new build

Hi all, I built a new system and just installed itunes and imported my old music library using the old hdd (actually moved all the songs over to the new hdd, then pointed itunes to it). Then when I went to sync, it said my ipod was sync'd to my old library, and had to either

Erase and Sync
Cancel

thats it, no other option. Now, except for play count (which I dont care about) and maybe a few song titles which had typos corrected, the music on both my hard drive and my ipod is exactly the same. BUT, the new install of itunes doesnt have any playlists on it. This I *do* care about and dont want to erase all my old playlists which I spent a lot of time on. They are only on my ipod it seems.

So what is the best way to resolve this? Is there a way to unsync my ipod from its old library and force it to sync with my new one? just the music - save the playlists.

I have an 8gb nano, and the latest version of itunes (dl like 20 min ago)

thanks!