Good firewalls should always block unwanted traffic whether it's inbound or outbound. This is not anything new, but you're right that most people trust the devices they own. Not anymore.
"Historically it's been very difficult to make detailed firewall configuration user-friendly. As a result, we've lived with the simplistic compromise of 'allow outgoing connections, don't allow incoming connections'. It seems like it's going to require some incredible new firewall configuration interface if we hope to make it possible for the ordinary clueless computer user to properly configure outgoing firewall rules."
However, if it became standard, then programs would tell users to check their firewall, and can even tell users the information that they need to fill into the firewall (eg. name of computer, port, ...).
Conceivably, you could define an protocol for devices to request an opening. This protocol could include a way of sending the password.
1. Block all network traffic, inbound and outbound.
2. When I decide that I need a specific network resource, enable it in a whitelist (i.e. enable traffic to/from news.ycombinator.com on port 80)
I wonder what that Internet would look like.