Quick Start Guide for the list of codecs and formats Wowza supports. Wowza can certainly stream MP3 files. And you can wrap the stream URI in an HTML5 video tag on a web page. But, the only browser I know that supports this is Safari on Mac using Cupertino streaming.
As you can see from your link (as of October 2011) the various browsers support different technologies... but things are rapidly changing. To the best of my knowledge, if you want to stream audio-only to the most devices you'll want to use AAC. Wowza can take a single stream and serve it to browsers via Flash or Silverlight, iOS with Cupertino, mobile devices and set-top boxes via RTSP. If you want to publish to Wowza using Flash, you can use the Speex protocol and then use the Wowza transcoder to convert to AAC.