Some UI features were not completed for IIS 7 running on Windows Vista. More work was put into the features themselves. The administration of some features was considered less useful for a developer computer. For instance, there was no UI available for configuring the logging feature on Windows Vista until Service Pack 1. It seemed less likely that developers using IIS 7 on Windows Vista would need to analyze log files as much as they would on Windows 2008 Server. Obviously the UI for these features were added to service pack 1 of Vista as they were completed for Windows 2008 Server anyway.
As stated, there is also some functionality added to the admin pack which allows you to edit configuration directly from the UI -- even if there is not a UI module provided for the configuration section in question.
I hope this helps.