> However, the positives of targeting any language at a stable byte code is incredibly valuable... such as an implementation of javascript itself. A bytecode approach provides a superset to our current status quo.

Not necessarily, it depends which bytecode. For example the bytecode in PNaCl, which is based on LLVM IR, is excellent for C and related languages, but not for many other important languages.

Worth reading this about the limitations of LLVM IR as a bytecode: http://lists.cs.uiuc.edu/pipermail/llvmdev/2011-October/0437...

I've also written a post about the limitations of any single bytecode to achieve all the goals the web needs: http://mozakai.blogspot.com/2013/05/the-elusive-universal-we...