I got linked to an MSDN blog and noticed that the URL was http://blogs.msdn.com/jensenh/archive/2005/11/08/490348.aspx. I don’t think that this is the actual folder structure on the server’s filesystem. I think it’s just what gets passed on to a script, that determines what content is being requested, and generates that content.
The “.aspx” must be deliberate. I think it’s an advertisement to anyone who programs computers that the website uses XML-based ASP (Active Server Pages, a Microsoft technology).
I think that this is pretty silly, because the extensions in the URLs are extra typing, are incorrect after switching languages, and don’t make things any easier for developers that are using URL dispatchers.
On the other hand, I think it’s a pretty slick move by Microsoft, and in some way I wouldn’t mind seeing it countered by Java, Python, and Ruby programmers.