Netcraft says http://orkut.com was running Microsoft-IIS on Solaris 8 when last queried at 8-Jul-2004 05:14:18 GMT.
Microsoft-IIS on Solaris 8?!
Google is working to build a host of new services like Gmail and Google Groups. Gmail and Google groups are integrated in the sense that I can use the same account across Gmail and Google Groups. But not Orkut. Going further, they will certainly want to integrate all of their services. At that point, the fact that they are using ASP.NET for Orkut will make them hit some roadblocks. And that is what gets me interested!
Or, they could be using an .aspx extension to fool people. Could they? :-)