Does Windows Vista really just add a new interface?

Many of my friends often think that Windows Vista is mainly changed on the interface. The fact is that the interface may indeed be one of the most attractive aspects of vista for common users, but it is also the most publicized, but in fact, Windows Vista has a lot of major improvements:

For example, kernel-level changes include:
CPU cycle counting
Multimedia class Scheduler Service
File-based Symbolic Links
I/O completion and Cancellation
I/O priority
Dynamic kernel address space
Memory priorities
Superfetch
There are many more...
For details, see Mark's three articles:
Http://www.microsoft.com/technet/technetmag/issues/2007/02/VistaKernel/
Http://www.microsoft.com/technet/technetmag/issues/2007/03/VistaKernel
Http://www.microsoft.com/technet/technetmag/issues/2007/04/VistaKernel

In addition, UAC & virtualization is a huge security improvement made by Vista. For details, refer
Http://technet.microsoft.com/en-us/windowsvista/aa906021.aspx

In Wikipedia, I have a complete article about Vista's new feature:
Http://en.wikipedia.org/wiki/Features_new_to_Windows_Vista