xSiteable is a somewhat complex framework for creating full sites based on Topic maps and simple notational language for content management. However, there are many things I would like to do to expand the capabilities and features of it. Here is a current list, off the top of my head;
topic indexing : Find all topics mentioned in a page, and list them in a general fashion. Not established what release this should be in, but it is not in my own immediate requirements, so some time after 1.0?
optimise : xSiteable ain't the quickest beast around, even if Sablotron is a fast one. One should use xsl:copy, xsl:map and pre-parsed trees for better performance. This is an ongoing task, so there is a bit of this in every release.
For a longer list of things that has been added or fixed, browse through the various releases, or read the xSiteable Logbook. If you feel items are missing from this list, have a look at Feature requests.