I have this installed on three of my machines, one of particular interrest might be the Latitude XT. Seems quite nice to use on the revised UI and even though this laptop has a 1.2GHz ULV it runs very smooth, but then Vista did an admirable job on this laptop aswell. So far one blue screen but to be expected.
Someone asked earlier if Kaspersky was safe to use and I can confirm that it certainly appears to be fine for me, although I am getting a few issues with it not reporting its status to the windows security centre.
I am also running a windows home server aswell, all of the machines have connected without any issue and have been recognised by the server as being Vista Ultimate Operating systems.
Also my main PC with TV cards etc in it that acts as a media centre host for the xbox attached to the TV seems to be working very well, no issues with setting up the extender at all. Slightly revised UI on media centre which is a little nicer. One big issue with this though, I seem to be getting mcGlidhost.exe crashes which VS just-in-time debugger is catching. I have reported this issue to MS, Im led to believe that im not the only person suffering from this issue either. Also gaming seems to be very good aswell, I have no idea of any performance differances but CoD runs as slick as ever!
Overall so far very impressed, seems to be incredibly stable for a beta! I thought Vista was a great OS and Windows 7 looks like it will offer further improvements!
PS one other little issue I have just noticed while writing this is that IE8 is not redrawing text correctly as I scroll up and down this input box!