Wow, this is ridiculous. After two days, and attempting the drag and drop method yesterday, unsuccessfully, it finally worked tonight and I don't know why. A few songs are still unplayable but at least I got most of my playlists updated. My free U2 SuperBowl download still won't play as it says my computer isn't authorized, but I guess I'll put up with that for now.
Okay so I found an easier solution other than going through and having to whipe your phone and restore it from a backup. What you do is...
(My estimated time for this process: 2-3 minutes not countring your sync time)
1. Plug in your iDevice(iPod/iPhone/iPad) using the USB cable like normal.
2. Go into the "Settings" application and select "Wi-Fi" on your iDevice(iPod/iPhone/iPad)
3. Turn ON your Wi-Fi connection on the device and select the network your computer is on.
4. Then return to the home screen of "settings"
5. In the third group of "Settings" on the home screen, at the top, There is a tab called "General" Select that tab.
6. Scroll to the very bottom and in the sixth group at the top of that group, you will see another tab labled "iTunes Wi-Fi Sync" This is the option you want to select.
7. On this page you're able to see the last time your device was able to sync with the computer. Near the bottom in group two, there is a a white tab with blue font saying "Sync Now". Click that tab.
8. Look at iTunes on your computer while your iDevice tries to sync. You should see "Copying items x of x" (x representing the number of items your device is trying to sync).
I hope this helped! Good luck!