Leif H. Wilden has released a Series 80 version of his OggPlay. OggPlay is not only an Ogg Vorbis player. Thanks to using Symbian's MMF (Multimedia Framework) and downloadable plugins it also supports built-in audio decoders (MP3, AAC, MP4) as well as decoders installed by users. And it's free!

http://symbianoggplay.sourceforge.net/S80MMF.html