All apps, music, and playlists are now missing

See Empty/corrupt iTunes library after upgrade/crash.

tt2

The exact same thing happened to me. I read the linked article, but there is no "Previous iTunes Libraries" folder shown anywhere in my iTunes folder.

This is the second time in a row that iTunes has randomly re-set itself after an upgrade and I've had to load everything from scratch again.

Did you check for the presence of *.tmp files?

I'd strongly recommend that you back up the library this time.

tt2

Yep, did a computer-wide search for both .itl and .tmp files, still no joy.

I looked at some of the other related threads and found a suggestion for getting the old library off a connected device, is that something that could be done manually? I synched my iPod really recently (like a day ago), so everything on there is current. But I am (I think understandably) extremely wary about hooking it up to my laptop due to the possibility of the new version of iTunes wiping the iPod clean. I did check the "don't synch automatically" box but I'd still feel a lot safer if there was a way to transfer things manually, i.e. without having iTunes open at the time.

Also finding some way to prevent this from happening again would be awfully nice. I've been using iTunes for ages and this is the first year I've had issues, but really there's not a lot of incentive to stick with a program if it's going to break itself every time it runs an automatic update.

See Recover your iTunes library from your iPod or iOS device. If we're talking non-iOS iPod start at the bottom of the table of recovery tools.

tt2