For (1): You're right that an option is to compile the VM itself to asm.js (since the VM is usually written C/C++ code; JITs are an obvious exception since they generate machine code at runtime). This has already been done, e.g., for Java [1] and Lua [2]. What is meant by "supporting GC languages" is translating GC objects in the source language to real JavaScript objects so that the JS GC may be used on them. For statically-typed source languages like .NET/JVM, the proposed Typed Objects extension to JavaScript [3] could be naturally integrated into asm.js to describe classes. This is all a little ways off since Typed Objects needs to be standardized first. Also, the lack of finalizers in JS would limit the fidelity of the translation.

For (2): yes, it is already being worked on [4].

[1] xmlvm.org [2] http://kripken.github.io/lua.vm.js/lua.vm.js.html [3] http://wiki.ecmascript.org/doku.php?id=harmony:typed_objects [4] http://badassjs.com/post/43158184752/qt-gui-toolkit-ported-t...