My argument would be that trying to protect against passive attackers with JS adds nothing beyond what SSL already offers.
Which is already required as a matter of course, and already compromises the payload if SSL is broken (again).
Again, I am not advocating JavaScript crypto. I'm just putting it in its place.
As pointed out elsewhere in the thread, there are few attacks that allow you to listen in on an SSL connection's content without also allowing you to modify that content - say, with a version that pastebins your keys.
Hence my argument that JS cannot provide anything SSL lacks, plus or minus some wishful thinking. Combine this with the fact that it's impossible to protect against a MITM-modified JS payload (see the "chicken-egg problem" portion), and you have a rather uphill battle here.