Caveat before we begin -- I understand that most of the time you should NOT style form controls but instead allow the OS to pick their appearance for interface consistency reasons. That said, these situations do eventually arise.
For those not familiar with them, Web Forms 2 are things like calendars, time controls, and so on (link to the W3C draft - note that they've been folded into the HTML 5 spec for further dev but that introduction should get you started).
What I'm curious about is how are we going to style these? Ever tried to style a check box? It isn't fun. So when a whole calendar is in the browser how are we going to be styling that thing?
I remember reading something the webkit team was working on that allowed styling of form pieces but it hasn't been adopted yet and is still experimental.
I'm looking for info like that, but also some ideas on how it might be done. Who knows, maybe one of the browser dev team members reads here.
Note - I see little reason to style a radio button or checkbox - but you have to admit that a calendar is a much more significant piece of design territory to delegate to the browser default.