Our trickplay/fastplay demo using the com.wowza.wms.module.ModuleFastPlay module is purely there as an example. The RTMP stream of the Extremists.flv can be played through the example browser code and provide 4x, 15x, 30x speed both forwards and backwards, though sped up or slowed down audio is not heard. You can get full trickplay features if playing the example Extremists.flv file through a player such as VLC, and when adding the advanced controls to the control bar it will allow you to drag forwards and backwards including audio at same speed.
I'm not aware of any future development of this functionality but will feed this back to our backlog queue. I can't give any timescales on when or if it gets released though.