It appears Google and Motorola have stepped in to make this idea actually happen. Codenamed "Ara ", Motorola claims they have been working on a concept very similar to Phonebloks for over a year now. I'm actually interested in seeing what
Google (Motorola's owned by Google) can bring to the table.
http://www.ibtimes.com/motorola-project-ara-can-google-make-phoneblok-style-smartphones-possible-1445730
http://www.youtube.com/watch?v=skXwTxo0Bo0