The most successful malleable system in history

I think good old RSS has a lot of potential as a malleable system component or backbone. RSS = message queue subscription protocol.

You can choose your app to consume RSS, then transform other content on the web into RSS feeds using various services. E.g. twitter posts -> RSS. If RSS goes beyond blogs it could be great. Could pageduty be replaced with an RSS feed, for example? Or even Email/SMS to some extent? Email is "expensive" to deliver in bulk (see Amazon SES etc.) but I wonder if an API for "people" delivered to them via RSS would provide a nice alternative with people releasing one-time tokens to avoid spam, and then making delivering a message to a bunch of people practically free like it should be.