Well, just found out that iPhone Config Utility 3.6.2 stops working after upgrade iTunes 12.1 on Windows. There is (actually) no new Config Utility available.
Does somebody know something about that?
As a workaround: uninstall AppleMobileSupport and install version from extracted iTunes 12.0.1.exe. Now you can use iPhoneConfigUtility again. Unfortunately, you need to install AppleMobileSupport from iTunes 12.1.exe again to use iTunes.
Whats going on there?