Actually I took it to mean more like wordpress.com and WPEngine - ie. things that people can self host if they want to deal with the hassles of it all.

Heroku doesn't (necessarily) host open source projects. And Github hosts source code, not applications.

Although Github may be more on the mark here then heroku since it is hosting git.

But I agree with dools, I think this prediction was about services like wordpress.

You are right, I read his whole description once again... :)