A heads up. I am looking to extend ExtendedType API to be a little more context-aware (know which attribute is being read/written). My motivation is quite interesting on its own - I need to implement generic data encryption extensions that would encrypt/decrypt certain columns on the fly. And I feel like ExtendedType is a place that is low-level enough to make the encryption transparent to the rest of the stack. Very excited about this project :)
A.