With regards to DocBook support:
qandaset table of contents Perhaps allow qandadiv elements to be nodes in Texinfo.
olink (do it like what the DocBook XSL stylesheets do)
synopfragmentref
Man pages should support qandaset, footnote, mediaobject, bridgehead, synopfragmentref sidebar, msgset, procedure (and there's more).
Some DocBook 4.0 stuff: e.g. methodsynopsis. On the other hand adding the DocBook 4.2 stuff shouldn't be that hard.
programlisting line numbering, and call-out bugs specified using area. Seems to need XSLT extensions though.
A template-based system for title pages, and biblioentry.
Setting column widths in tables are not yet supported in man pages, but they should be.
For other work items, see the “limitations” or “bugs” section in the individual tools’ reference pages.
Other work items:
Improve the stylesheet documentation.
Write documentation for Man-XML and Texi-XML. Write a smaller application (smaller than DocBook, that is!) of Man-XML and/or Texi-XML (e.g. for W3C specs). A side benefit is that we can identify any bugs or design misfeatures that are not noticed in the DocBook application.
Figure out some way for manuals not written in a strict reference style (like this one, and most Texinfo-based manuals) to be condensed or summarized automatically into man pages, without having to explicitly write material in the refentry format.
Need to go through the stylesheets and check/fill in any missing DocBook functionality. Make a table outlining what part of DocBook we support.
For example, we have to check that each attribute is actually supported for an element that we claim to support, or else at least raise a warning to the user when that attribute is used.
Also some of the DocBook elements are not rendered very nicely even when they are supported.
Fault-tolerant, complete error handling.
Full localization for the output, as well as the messages from docbook2X programs. (Note that we already have internationalization for the output.)
Do away with the automake bloat.