Any thoughts to use multiple buttons to control things? For example, up and left at the same time. You could use it for the "mark track" feature. You could also regain the ability to search through tracks without using the remote this way.

Besides, the way the controls SHOULD work IMO to be more intuative is this:

up or down held - volume up/down
left or right held - rewind/ff
press left or right - track back/forward

Then, for example:

up & down - change input (fm/empeg/aux)
other combinations to mark tracks, etc...

Also it would be cool to be able to have a priority associated with a song, maybe low, neutral, and high, and you could quickly mark songs as they show up in the shuffle.