Okay, so lets assume you're the product owner for Windows settings. You have full, dictatorial control over the Windows settings experience. Windows 7 has reached maturity, and you and your team are starting planning for Windows 8 and beyond. You have identified a number of major flaws in the Windows settings experience, and you want to update it for the future. What do you do?
Note that the Windows settings codebase is huge, has thousands of possible settings options that you can set, and the specific esoteric behavior of those settings is relied on by users, developers and sysadmins every day.
MS clearly decided to re-do the settings system over multiple Windows generations because it was too big to do in a single release cycle. During the transition period, both Settings and Control Panel tooling will be available, and used by many users. Is there any other alternative?