Peruta might be done, but the other two companion cases are not done by any stretch of the imagination. Richards v
Prieto and Baker v
Kealoha were both decided completely based on Peruta. Both of those decisions are pending the decision on their applications for en banc rehearing by CA9.
What happened in Peruta is purely procedural in that the CA AG, Brady Campaign, and two other groups were denied intervenor status when the Sheriff of San Diego County declined to appeal to for an En Banc rehearing.
The other two cases are quite viable and if CA9 decides to grant an en banc rehearing to either or both, they and by extension Peruta could be overturned.
If en banc is denied in both cases, then it's no doubt on to a petition to SCOTUS for cert. Since there is a clear split among Circuits right now, there is a good chance that will be granted, although as was the case in IL with Moore v Madigan, there will be a tremendous amount of pressure on both CA and Hawaii to not press the issue and let CA become shall issue.
The Truth About Guns people seem to have this entirely wrong.
This
article in the Washington Post by Prof. Eugene Volokh explains it quite well.
The issue is far from settled.