Should we embed virtual machines rather than languages

Question

Ok, so I am trying to learn front-end programming. Trying to figure out how javascript is a pain, and various projects (GWT, Coffeescript, Capuccino's objective/j...) are trying to fix this with languages that compile to JS.

What would you do if you were to reinvent the browser?

I think I would embed a VM rather than a language (quite like Java applets except less complex and with a DOM API instead of a canvas and self-contained environment).

I suppose this has been suggested many times, but I cannot find resources on this, and most of the embedding tutorial I stumble on address embedding languages (guile, lua, python, whatever).

Thoughts?