In the Pet clinic I found the CustomDatePickerBinder that uses JXDatePicker.
When I enabled it, it worked, but not good enough I think.
Have you considered support for nachocalendar?
It looks a lot more mature to me.
Spring RCP could have support for both, in a spring like way under
- NachoCalendarDateBinder (the new default if it's any good)
- TheCurrentDefaultDateBinder (with better name)