Just got my hands on the new Gopro HERO3+. There are a bunch of new features which can be discussed in this thread. The most obvious one that should be mentioned is the new housing. It's a little smaller and more compact than the previous HERO3 housing. Looks like Gopro chose to up-sell the previous standard HERO3 housing as an optional HERO3+ Dive housing to those who want to feel safe diving with the Gopro.
I think buying the HERO3 dive housing is a must for spearfishing videos. Not necessarily because of the higher underwater rating, 60m versus the new housing with a stated 40m depth rating. But because the new housing doesn't have the secondary latch, without which the housing door can potentially open from the speargun recoil (if mounted on a speargun). You'd have to resort to a backup solution like a zip-tie or rubber band around the housing latch.
GoPro HERO3+ cameras are available from www.FreediveStore.com with a free diving accessory included.
GoPro HERO3+ new housing