I came upon this library as a result of trying to deal with this independent/dependent property situation.
The solution I keep finding myself using is to just fire additional property changed events for the dependent properties from the setter of various independent properties.
It does feel a little bit icky, but seems to work ok for my purposes. I think its OK if the model classes are relatively simple, and I find the whole wpf data binding thing pretty heavy on the black magic scale as it is, without introducing yet another
layer into the mix.