Earlier quoted context omitted.
Maybe nothing should be web apps... maybe the pipe is for content and services, and native code is for layout and interaction...
So are you willing to have native code pushed to you with no control over it? Because that's the major logistical advantage of webapps that has Enterprises trying to use them. Maybe when NaCL gets better...
Java bytecode is excellent precedent for what is broadly possible. There are problems with it, but most of what's missing for the end user is a better degree of convenience and control.