Syncing phone after reinstalling my OS

Hello!

I have a concern right now about syncing my iphone 4Gs. Obviously, when you sync your phone, it syncs with your library. My concern is that I just did a clean sweep of my harddrive. I had everything backed up though, and I still have all the music currently on my phone.

My concern is that if I try and sync the phone with my new library, (because the apps and other stuff (like my notes) were synced with my old library), it will wipe all the current stuff on my phone.

Obviously I could transfer the purchases, but wouldn't that wipe all the data inside my current apps?

Again, my old library is totally backed up on my removable HD, if thats important at all.

Any and all help would be greatly appreciated!!

 

Thanks, but my concern is syncing the phone w/ itunes going forward (not just making sure I have everything backed up)