While the NTSB is free to recommend to their heart's content, it's another thing entirely for the FAA to adopt the idea. The NTSB has had many many recommendations sit there with no action for years.
This rule seems destined to sit as well, as airlines won't want to pay to install cameras and pilots won't want to be filmed. With countries all over the world deciding to use voice recorders as evidence in criminal prosecutions, I for one have no faith in any guarantee that video would be used solely for accident investigations.