Both Nick and I struck the same problem so I'm guessing that it may be a common issue for others trying to install Visual Studio 2005 Beta 2 on Windows Vista Beta 1.
The installer for VS complains that it can't find the MSXML 6.0 Parser and stops the installation of Visual Studio.
I got it to work by sharing out the DVD Drive and then connecting to it via it's UNC name eg \\machinename\dvd and then navigating to the "vs" directory and running setup.exe from there.
For some this solution did not work so try the following and probably simplier approach:-
Once you've got the MSXML 6.0 Parser installed out of band then VS 2005 B2 should install just fine:-)
And all is good!!
BTW and I really can't remember where I read this but I'm pretty sure you need to stick with the offical April Beta 2 rather than tempting fate with a more recent CTP build.
Update 1Yes, you must stick with Beta 2 of Visual Studio and the Framework - see comment posted below...
Update 2To run Windows Presentation Foundation (Avalon) or Communications Foundation (Indigo) you need to install the runtime - on the Vista DVD you can find this under the \support\winfx directory.
For Windows XP SP2, you can download the beta 1 runtime from http://msdn.microsoft.com/windowsvista/.
At the very least on either Windows Vista or XP SP2 you should install:-
From very brief search I spotted http://www.therhogue.com/WinFX/ Windows Presentation Foundation samples, tried a couple on beta1 of the WinFX runtime and they seemed to work just fine.
But basically keep an eye on the http://msdn.microsoft.com/windowsvista/ and what's new on the Windows Vista MSDN RSS feed at http://msdn.microsoft.com/windowsvista/rss.xml