As recently seen on my blog... in case anyone else is using the Visual Studio route for making their installer and are sick of using Orca to manually add the WHS key every time... you might try this bit for a post-build step to automatically add the WHSLogo key every time (so long as you have WiRunSQL.vbs installed (included in the Windows SDK)):
"C:\Program Files\Microsoft SDKs\Windows\v6.0\Samples\SysMgmt\MSI\scripts\WiRunSQL.vbs" "$(BuiltOuputPath)" "INSERT INTO Property(Property.Property, Property.Value) VALUES('WHSLogo', 1)"