sorry, currently I'm unaware of such solution. But I guess sooner or later, some more experienced script programmer will appear and write simple script that will traverse media directories, recognize cover art in several "standard" ways (also like Xlobby does) and that will be solution....
Maybe we can start a list of possibilities (I'll start):
1. if same filename exists with .png or.jpg then this is coverart
2. if files have no separate coverarts under 1., then you take existing folder.jpg(png) or .folder or (
).... as cover art
Anyone already there ?