OK so there is a minor practical problem with Windows Vista in it's current Beta form - if you suspend or hibernate your system the display doesn't come back up (on my machine anyway).
Thanks to James for sharing with me the tip to get it to come back on - it's weird but strangely it works every time! All you have to do (assuming you're running on a laptop!) is to remove the external power momentarily - the display works perfectly afterwards :-)
James' recent Windows Vista article is well worth a read as he links to BillGates' video as recorded at WinHEC.