Along those lines, it sounds like Sandstorm may be a fit for what you're thinking of. It's generally more federated than a totally distributed system, but provides nice mechanics for packaging web apps, distributing them to others, moving from one server to another, sandboxing them, etc. It makes setting up and running web apps as easy and safe as downloading an app from an app store.
The rate of change for features for the open source sort has not changed drastically, as a lot of effort was being expended on business development and profitability before the funding dried up.
