The magic happens inside the flash player, so all you'd need to do to get the same effect is place that flash player inside an aspx page (or ascx control) and supply the appropriate variables like the file name and location of the audio.
Does that answer the question or am I missing something?
Well, for the player portion, you could use the Yahoo! Music Player: http://mediaplayer.yahoo.com/
I know that's not exactly what you're looking for, as you want all the features of PodPress, but, I imagine this could be a small stepping-stone/starting point. It's really easy to use, and it's a decent interface.
I don't think there's a simple answer to this question. podPress is a quite a large plugin, and porting it to a new language and blog engine is tough; there's not just a single trick to it. I imagine that the included Flash and Java players and the supporting JavaScript is licensed so that you can use them in your project. (podPress is GPL)
Now, the StackOverflow blog uses WordPress and podPress, not something written in .NET, so my bet is that nobody has actually done this work.
I wonder if anyone has any idea on how to implement the nice and clean UI from PodPress (a Wordpress plugin) into .NET just like you find in the StackOverflow Blog when PodCasts are available.
I'm searching for the entire bottle of magic, iTunes integration, Stats, etc... Shouldn't Jeff give an anwer, he had to do something about this?
Jeff didn't convert PodPress into .NET.
blog.Stackoverflow.com is a Wordpress blog.
He simply loaded the PodPress plugin for Wordpress, clicked activate in his plugins tab and navigated to his newly created PodPress tab. There he configured his iTunes integration and his statistics information.
If you view the source of the blog you'll see:
<meta name="generator" content="WordPress 2.7" />
Edit: Response to your comment.
Yes, I realized that after, but still... I WANT a .NET version :) (not to much to ask, is it?) eheh ;) – balexandre
The PodPress-WordPress plugin is tightly coupled to the WordPress Plugin Interface. PodPress is a mixture of flash, javascript and php and all of these are calling upon WordPress functions.
The PHP and Javascript are easily editable but the work required to hack PodPress to work without WordPress would probably be a little more difficult than simply re-writing PodPress from scratch.
Also, I've read on many forums about people getting slow responses from the sole developer of the project and how releases have been taking a long while to come out. So I don't think you'll be able to easily get him to rewrite his project into a different platform.
Your options are: