There is still one more option other than a reinstall of iTunes.
Have you considered updating SL to 10.6.7 which is the most current version? I recently upgraded from OSX 10.5.8 on my MacBook to SL 10.6.3 using the install disk that came the Mac Boxed Set (included iWork '09 and iLife '11) and experienced the same problem as you.
When I first tried to sync my iPad with the new OS (10.6.3), iTunes would not recognize the device. I had been using the iPad for 6 months without a single issue while running 10.5.8. so I was somewhat bummed. (I performed a Time Machine Backup prior to installing SL just in case)
I rebooted both devices and still no luck. As I was fiddling around try to figure out what to do, Software Update popped up as there were further updates to the SL software. I decided I had nothing to lose so I updated all the way to 10.6.7, rebooted both devices and the iPad was recognized in iTunes just as it should be.
My point is with 10.6.3 I could not get iTunes to recognize my iPad. Once I updated all the way to 10.6.7 all was right with the Apple World again.
Quick addition - iOS 4.3.3 is now out so you can update the iPad as well once you get this resolved. There is also a further update to iTunes - 10.2.2.
Message was edited by: Demo