iTunes management with multiple PC's
I recently purchased a new (Windows 7) laptop and would like to use it to manage my iPhone and music library. I have about 40 gigs of music which can easily fit onto the new laptop, however, since my aging desktop has 2TB of storage they are a much better fit there. Also, the desktop has been managing iTunes forever so it has my "star ratings" as well as times played counter. Maybe feeble, but still it takes a while to get up to that. It has also been my iPhone's "master" since I purchased the iPhone in October 2011.
Is it possible to have both of these PCs manage the iPhone and not lose the data? Or is my best setup to convert the laptop to the main manager and use the desktop to "share" the music library off the laptop, which would mean I would need to turn the laptop on whenever I wanted to play music off the desktop (which is daily at 12:30 am while I telecommute to work)?