If it's not MP3, is it still podcasting?

Winer also blogs that the MP3 format was chosen for its limitations as much as its flexibility:

By design, podcasting took a poison pill at the very beginning of its life that made it impossible for the corporate types to subvert it without fundamentally changing what it is. That's why I was sure that Audible wasn't doing podcasting.

Only MP3 provides the portability and compatibility that users depend on. Any other method will force them to jump through hoops that they will resist. If so, then podcasting isn't for the advertisers. They keep insisting that it is, and that we old timers are just resisting the inevitable, but honestly they're wrong -- they should learn a little technology before they tell us how it is. I've taken the time to discuss it with them, and look forward to the post mortem when we look at why what they tried to do didn't work. It's not likely, but maybe then they will have found some new respect for technology.

Source: Dave Winer