As I noted some time ago, it's hard to get programmers excited about power management. What's worse, programs that do take the effort to care about power management often do it rudely, hijacking your computer and preventing you from going into standby or hibernation, instead preferring to drain your battery until the computer just dies from lack of power.
The Power Management folks decided that they've had enough with these selfish programs and redesigned the way power management works. In addition to exposing finer control over various aspects of power management to the user, they also decided to "take the ball and go home" when it comes to programs rejecting suspend or hibernation requests. When the user asks for the computer to go into a low power state, programs will get notified of the state change but are not allowed to veto it. Programs get two seconds to clean up, and then that's it. The laptop is going into standby, ready or not.
If you ordered a copy of the PDC DVDs, you can go back and watch session FUN319 to learn more. (Here are some follow-up remarks to that session.) I'm not the expert in this area; I'm just repeating what I've heard. If you have questions about the future of power management, you probably should ask the power management folks over on the Windows Mobile PC Team Blog.