I've been looking at the current expl3 work, and I'm wondering about the
planned direction with keyval stuff. The current l3keyval only covers
some very basic functions, and it's not clear to me whether this will be
extended to higher-level commands.
As I see it, something based on either kvoptions or pgfkeys wouls be
useful for defining package options and so forth: the "template"
mechanism does not cover all cases (I think, at least). Assuming I've
not missed something on the template side, are there any plans to extend
the current l3keyval or provide some other higher-level system?
My current method is to hack kvoptions to do the right sort of thing
(for example, modifying \DeclareStringoption to add both a pre- and
postfix to the string macro name). However, if no-one else is likely to
work on this in the near future I can perhaps see whether I can produce
some basic macros in this area (for preference I'd probably adopt the
pgfopts model, which I find quite accessible).