First off, if you’re installing Visual Studio 2008 beta 2 and want some Silverlight love, don’t uncheck Visual Web Developer from the installer! If you do, the Silverlight Tools for VS beta 2 installer will tell you that VS 2008 isn’t installed. You may proceed to bang your head on the desk for several hours, reinstall a few times, and even contact the Silverlight team to save your sorry ass (thanks guys! ). All will be in vain without that checkbox, so leave it alone!
Also, if you’re already using Orcas beta 1, do not under any circumstances delete your installation source before uninstalling it (a particularly tempting proposition if you installed through Virtual Clonedrive or Daemon Tools, rather than burn a disk like a normal person).
Hopefully these tips will save you some distress .