Put ASP.NET on wordpress site
Since asking this question a long time ago and creating a less than ideal iframe solution I have now found a great wordpress plugin called iframe-less
http://wordpress.org/extend/plugins/iframe-less-plugin/
Basically you give it an URL and it builds the content of that page directly into your wordpress page. So far it seems to work really well.
I have similar needs that the originator of this thread has. I maintain a CRM and corporate site that runs on ASP.NET/SQL along with a separate Wordpress php company blog. After we've been using Wordpress for a year, people here would love to be able to edit static content on our corporate site like we do in Wordpress, so I am looking at possible ASP.NET/Wordpress hybrid set ups.
I am hearing good things about "Phalanger": http://www.php-compiler.netIt is a PHP Language Compiler for the .NET Framework, and you can run PHP code in .NET
It was also great to find out in this thread that you can have PHP and ASP.NET in the same IIS web, its another reasonable sounding solution. If I had any nay reputation (I am new here) I'd give RickNZ a vote.