I vaguely remember some folks not being able to sync in the past. If my memory serves me, trying disabling your internet connection first, then attempt a sync. Something to do with a crash report server. That might work.
hmh.. I'm fresh out of ideas. Other may have some clues, but I'm going to suggest a restore of the phone. Hopefully you have all of your contacts and data backed up already.
Connect your iPhone to your computer.
Turn iPhone off.
Hold power and home together for 10 seconds (exactly).
Release power but keep holding home until the computers beeps as a USB device is recognized.
A few seconds later iTunes should detect your iPhone.
Restore from there