Is this a retail Ultimate key, or one which came preinstalled on the old laptop which cannot be moved?
If it's a retail key you can insert it into Anytime Upgrade to unlock the few additional expensive Ultimate features which the vast majority of users don't need. Windows Anytime Upgrade - How to - Windows 7 Forums
I would first make your new laptop Recovery Disks and save externally a Windows 7 backup image of Home Premium so you can revert if you find another place you'd like to use Ultimate and not waste the $100+ Home Premium license which came with the new laptop. Backup Complete Computer - Create an Image Backup
Then make a Windows 7 backup image of the new Ultimate installation to use in place of reinstalls.
Be sure to also make the System Repair Disk
to use in case Windows 7 becomes unbootable. You can also use the Ultimate install disk if you have it, for repairs or clean reinstall.