If we're talking about a JVM impl (rather than a source-to-source compiler á la GWT), being able to use better languages like Clojure, Python (via Jython), Ruby (via JRuby), et al. would be a huge reason.
Fair enough. Though if you want to write code that looks like Python or Ruby, I can't recommend CoffeeScript (or Coco, if you're feeling frisky) enough.
Hmmm, I'd assumed it was a source-to-source compiler. Are they thinking of writing a JVM in JavaScript? Can you say slow? And debugging seems like a nightmare. And if it's not that, then how else does it get into the browser?
Presumably, that's what Orto did (a post about which I linked to in the original post), and apparently with reasonable performance results for the examples they provided at the time (circa 2008). Javascript runtimes are becoming absurdly fast these days, so I wouldn't put an efficient and effective JVM-in-Javascript out of reach on spec, at least not yet.
