The final version of the guidelines look a lot like the draft -- pistols with security devices must be able to disable the weapon's firing mechanism when not in the control of an authorized individual. The security features of smart guns need to be a permanent part of the weapon too, though they are allowed to incorporate external verification accessories like rings, tokens or wristbands.
Also like the draft, most of the guidelines are about what smart gun security features can't do -- impair operation or increase time needed to draw, holster or fire the weapon. If a firearm's security features are malfunctioning, they also need to default to unlocking the weapon. If that sounds pretty lax, it's supposed to be: the department says the project is designed to spur the growth of gun safety technology without limiting innovation by choosing a standard too soon.
As nice as it is to see these guidelines developed, it's important to remember that they're optional: this is a voluntary list of specifications. Even so, there's a good chance the industry will adopt it all the same -- these aren't just the standards the Department of Justice wants to see in the future of smart guns, it's the baseline requirement government buyers will look for when they purchase firearms for law enforcement agencies, too.