I've been busy building out demo enviornments on various pieces of hardware. I'm running Windows Server 2008 R2 on a laptop with the Hyper-V role enabled. This of course disabled hibernation and sleep. I don't need my VM's running all of the time on the laptop, so it would be nice to be able to just close the lid and let the machine go to sleep.
You can set the hypervisor not to run automatically at boot quite easily. This gives you the hibernation and sleep options back. When you do want to spin up some VM's, you can start the hypervisor and away you go. Unfortunatly you'll have to restart the OS to shutdown the hypervisor again, but thats not too much hassle is it?
sc config hvboot start= demand
Note that there is space between the = and demand
When you want to spin up your VM's just run
net start hvboot