Upgrading

So I am getting a brand new iMac tomorrow (upgrading from my late 2008 MacBook Pro, very excited!) Couple of questions on upgrading.

1) Time machine: I have a drive that I have been using as my time machine back up drive. I would like to keep using it for the back up drive for the new machine but I do not want to loose all the old back ups. Is that possible?

2) iTunes: How do I transfer my playlists (not just the music and video files but the actual playlists) to the new computer.

thanks all
-SPG