It takes forever, I have no need for it. I already unchecked the Sync Apps checkbox, but it copies the apps off the phone anyway. I don't want to deauthorize the computer, because I do sync music and podcasts to my phone.
So the only way to do this is to create a new iTunes library. I tried simply deactivating the computer, but this still causes pop up messages to appear every time you sync your phone, asking you to reactivate your pc. You can just click no, but its still annoying because you can't just click sync and walk away.