We've found quite an interesting project announcement at
Grauw's web spot. Grauw had the idea of making MSX-DOS3 (as a kind of successor to ASCII's/Microsoft's MSX-DOS and MSX-DOS2), which would at least be MSX-DOS2 compatible. He decided to dedicate a complete web page to this project, which you can find
over here.
Although he says the amount of already written code is not that impressive, he seems to have worked out quite some details. Aside from some technical ideas and the feature list, Grauw also put his motivation on this page.
Relevant link:
Grauw's web spot - DOS 3