On MSDN in the ASP.NET Community there's an interesting question:
Visual Studio .NET creates Web applications using the Code-Behind model, while Web Matrix creates them until the Code-Inside model. Visual Studio 2005 will add yet a third model (Code-beside). Which should you use?
The opinions of 4 experts are given.
I'd like to know what other people thinks about it.
Personally I like the separation of ASPX and source code. A Web Designer can work on the graphic part of the site (HTML) and a developer can work on the source code... there's a good level separation and I like this "layered" vision.
However, Dino explanation is good. The future VS.NET Whidbey will introduce the code-beside model, which seems to be an excellent combination of the original idea of code-behind with VS.NET IntelliSense-related needs. Advantages? Maybe a lot...