Another issue that's periodically come up, and would seem all the more relevant with the DocBook project (which will hopefully be incorporated into ConTeXt itself at some point):
There are a number of structures that, AFAIK, do not yet exist in ConTeXt, but should. Ones that are a) in DocBook, b) broadly useful, and c) useful to me :-):
subtitle author abstract (and other such meta info)
Any plans to add these? It'd certainly make customizing DocBook output, ConTeXt stuff itself, easier as well as...
And here's a wild thought (though I don't know if a good one):
Why not link the meta info stuff to the forthcoming new bib system? I have a new article I'm working on in ConTeXt:
I enter it in the bib database complete with abstract and a status of draft, and the meta information gets imported into the document.