Can it be done? I'm thinking along the lines of :hover.. :visited etc; Could I register my own psuedoclasses? ;) X.Y:Z would be handy for situations where X.Y isn't definitive enough, and X.Y#Z wont work because there's more than 1 Z-type thing on a page.
Using Javascipt to bind objects is acceptable, but how could it be/can it be done? O_o