Hey, Josh, I posted this just now on the Zune Review thread, but what the heck:
For syncing errors, try these:
1) Connect the Zune to a USB port at the back of your PC, not the front
2) Connect it directly to the PC, and not through a USB Hub
3) Try reinstalling the Zune software if this happens too often
4) Download a more current release of the Zune software from Microsoft's website
5) If you do opt for option #4, then try Microsoft's tips (also on their website) for a clean uninstall of your original Zune software first