What challenges do we face?
If you were asked as an IT function to rollout Windows 7 as an OS tomorrow would this be a real challenge? After all, even the most complicated and locked down desktop build should be completed in a couple of days and then deployment of this will take longer, depending on your existing deployment mechanisms.
The real challenge is based in getting your application estate to work with Windows 7, or whatever the new OS happens to be. Transitioning your applications between OS versions and ensuring that these will still function and operate is the real challenge.
In addition consider what value your end user community will get from this shiny new OS, or put another way does your end user community, in the main, work with the OS or simply use this as a window to access applications?
We believe there is a very strong case to suggest that we ultimately need to concern ourselves with applications and our project approach, and in particular our Strategic Assessment services (link to this), directly reflect the importance of applications in defining desktop strategy.