Sleepy Microsoft Vista performance ?

Checking out Microsoft's new Vista operating system, I was surprised to see that the otherwise solid marketing was let down if you zoom in on performance.
The first 3 bullets concerning Vista performance are:

1. Sleep
2. Sleep on desktop PCs
3. Sleep on laptop PCs

Hardly subjects that make you think of a fast OS. (The whole performance page mentions 'sleep' 16 times ...).
Combined with the news of a delayed roll-out, maybe the Microsoft developers have allowed themselves some sleep ...