1) Installed VS.NET 2005 Beta 2 on an AMD 3400+ with Windows Server 64Bit version, without a hitch!
2) If you want your ASP.NET 2.0 web apps in IIS to run properly, have to drop to the Framework 2.0 32 bit Framework (you may have both 32 bit and 64 bit frameworks) folder and run ASPNET_REGIIS -i -wow64
The -wow64 switch is required for a full install on 64 bit machines. Otherwise, when you attempt to run or debug your app, you will get an HTTP "Service Unavailable" error.
Word to the wise.