I really like this article when I talk with ISVs about Windows Vista and how to get the most bang out of their development efforts in supporting Windows Vista.  This article walks you through where we think the "Light Up" scenarios are in Vista.   

http://msdn.microsoft.com/windowsvista/prodinfo/top10/default.aspx 

As for taking the Operating System mobile,  here you get an introduction to mobile pc challenges that Windows Vista can help solve, including power management, network awareness, providing offline access to important data, taking advantage of multiple displays, grab-and-go docking, and readability.   
http://msdn.microsoft.com/windowsvista/prodinfo/what/mobile/default.aspx

Cheers, James