After installing IE 8 on Vista, Visual C++ 2008's webbrowser-based wizard reports script errors and does not generate correct code. Looks like Visual Studio always inherit new IE features instead of opt-in. I have similar issues when upgrade from IE6 to IE7.
Adding devenv.exe to HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION with the value 7000 does not help.
Also reported in IE feedback
Walkaround posted by the VC team