I know you want to make migrating Visual Studio 2003 Web projects to Visual Studio 2005 as painless as possible.
I feel models save a lot of time. Take a look at these two web sites.
"There's a preview http://webproject.scottgu.com/Download.aspx of the Visual Studio 2005 Web Application Project http://weblogs.asp.net/scottgu/archive/2005/12/07/432630.aspx. This new project model is an add-in to VS 2005 that provides the same conceptual project model that existed in Visual Studio 2003 but with all the new designer features of Visual Studio 2005 and ASP.NET 2.0."