Using webintents to enable HTML+JS plugins

Crazy idea alert!

Assuming we invent an intent to handle a mime type (the View intent), then
I could imagine
it opening up the possibility to not only support explicitly started
activities to handle a
particular mime type, but also the incidental encountering of mime types
(<iframe>) or the
explicit embedding of a plugin to handle a mime type (<embed>/<object>).

Traditionally, browser invoke plugins to handle non-built-in mime types.
 It seems
WebIntents could enable HTML+JS to be used to do the same.  I'm sure there
are plenty
of details to work out about how an <embed> tag would magically have HTML
content
loaded beneath it, etc.

There's also details about how the "document data stream" would be surfaced
to the content.
One could imagine using Blob or some other streaming mechanism.

Crazy idea?

-Darin