@Margaret: Graeme's reply shows a fairly simple way to achieve it today, without needing to wait for built in support. It doesn't account for updating the color coding as you type, but you could achieve that with a timer, and perhaps only parsing the lines that are currently visible.
On a related note, does anyone know if there is some kind of _beforecommand_ and/or _aftercommand_ hook? I have a growing number of small modifications to the C/C++ as-you-type formatting engine (which I intend to share with the SlickTeam when the modifications are finished), and to finish porting some of the as-you-type smarts I had written in another editor, I really need some kind of _beforecommand_ and _aftercommand_ hooks.