The awesome Pacemaker DJ beat matching app just got a nice update to v1.2.0.4 this week. The Lite version does not seem to be updated but the pro version did get the update. From what I can tell this version added ACC (.mp4) file attachment and audio support which is the format for iTunes. Let us know if you spot anything else.
You can find Pacemaker in App World here and a free trial here. More info about the capabilities is available at pacemaker.net.