I was researching players to day and came accross a real nice one, I think this one rivals RockPlayer and for a better price, the application is called Meridian Player (I know a strange name ) but I downloaded the trial and I am really considering buying this one.... Its only 2.99 compared to the 9.99 for Rock Player. Another nice feature this player can play in Landscape and Portriat mode.... Give you a little more control of your device.
Check it out at http://www.androidtapp.com/meridian-player/ (Sorry Corredted Link - Copied wrong one....)
and let me know what you think... It is a universal player for music, videos and play list. check out video at http://www.youtube.com/watch?v=Rs14gKe2TrI but keep in mind the software has been updated since this videos.