I’ll chime in on the issue–not to fan the flames–but as a new member, to offer a perspective that may (or may not) have been offered already:
The idea of folder-based organization is appealing. I do a considerable amount of high-level (e.g., Visual Basic, Matlab, etc.) programming, which includes built-in functions that easily allow the programmer to build multiple data structures and interfaces for accessing the data. I could build a clone of the Clip interface in Visual Basic (using ActiveX controls for audio playback) in under an hour, and include FOLDERS!!! However, coding the same thing at the machine level (embedded-system programming) is way beyond my skill-level. I have no sense for how hard it would be, and for the record, have a hard time believing anyone who chimes in here as an authority, and ISN’T working with Rockbox!
Now the pragmatic question. Why folders? Because you to want to create groupings for mood, occasion, whatever. But really that idea doesn’t make sense…or rather, that idea ONLY makes sense with playlists. Why? Because you’d probably never duplicate a song in multiple folders (that’s inefficient), but with playlists it costs almost nothing to put a song on two or more playlists. So I’d argue, at the functional level, that playlists trump folders.
-Matt
