Don't force the technology worker to use one brand for a SmartPhone (Blackberry, Android, MS Windows, Apple). Leverage what the user is already buying. Give the end user a set amount of funds to purchase technology every three years.
I believe if the USG continues an isolated platform strategy then they will continue to get suboptimal solutions.
For example, the consistent believe that "Windows is the platform" leads to the Windows team being group to pick the browser (IE) leading to outdated solutions for a modern world.
A successful mobile solution needs to make the browser the platform and divorce this from a Windows-centric view of IT.