Sounds good to me. It would be cool if you could build in the time zone difference calcs like I described here http://chillenious.wordpress.com/2007/02/06/49/ (and like are implemented in various classes of the datetime project). Personally, I'd prefer such a datepicker to be in wicket-datetime over one in wicket-extensions now, as it is nice to group all similar comps like together (easy to find for users) and it'll keep the project relevant on it's own.
That is done by the current converter class in the datetime project isn't it (with use of joda?) I do exactly the same thing in java in the new datepicker as the wicket=datetime does i only render out some different javascript. johan