A new release has just been published to the market.
This release adds Variable Speed Playback.
It is at an EXPERIMENTAL stage. You can enable variable speed in Preferences/Audio.
If you have issues or feedback, please go to the support forum and read the variable speed sticky post. Please do not send emails to support regarding variable speed.
This feature does require the purchase of an Android audio library called Presto. Once this feature is enabled in the preferences, you'll see a 1x button in the media player. Click on it to get to Presto in the Google Market.