Probably not worth it, the current scheme, though clunky and awkward, works OK.
For now, at least.
What we've talked about is making a theme manager package (xarg, when they were around, did a simple one) that would allow the uploading of tarballs or zips of css files and then create the theme internals for you (presumably using the openacs default masters). Even simpler skinning than the new theme package stuff gets you...
