Reconstructing the dead from their communications?

If you had access to every email, every voice conversation, every document, every photo, every work of art, every blog post, a person ever created, public and private, how accurately do you think a dedicated scholar and highly talented character actor could emulate them?  

Researchers are playing with pervasive life recording devices that will gather the data that could make this sort of thing possible.  I believe that in the future, an advanced artificial intelligence would be able to use this data to essentially bring this person back from the dead.  Even though you would not have access to their internal monologue, it's likely a lot of it could be guessed by observing the "boundary conditions" -- their actions in the world.  The task would be made even easier if, in the future, fully detailed (down to the synapse level) models of different human brains become available.  This would turn reverse-engineering a particular person's brain from a black box problem into more of a white box problem.