2013 edition was the one released in July and it was his second edition since 2011 which was the first edition. He didn't make changes until there was a collection of errata and the changes included the errata. He added no new sections, just edited things that needed editing. The videos are always updated and released to the server immediately.
So if you wait for a new edition you'll probably be waiting till your done with clinicals by then.
Also, when he released the new version he gave people the option to upgrade their textbook for, i think it was, 19.99 + 6 bucks shipping fedex.