I have just installed the Windows 8 Release Preview in a dual boot configuration. I have noticed a couple of problems.
One is that if I click on the default picture screen on startup, the login screen is no longer working. I just see a blank background-colour screen instead of the password prompt.
Before this, I had problems with a non-responsive start screen, the buttons would move but nothing else would happen. I had to shut down, the option to power down didn't work either.
I'm using a Lenovo T410 with i5 530 and an OCZ Petrol.
When I reinstalled windows 8, I could login, but before long, the disk usage would go to 100 %, without any process using much CPU. I tried to see which process was using all the writes or reads, but task manager wasn't showing much in the way of IO, and the machine was not responsive, except for a few seconds at a time. I'm hoping the release version works better. I have since booted into windows 7 and deleted the windows 8 partition.