But all these algorithms (including compilation to native code) are already in use in JRuby, Topaz, Truffle, PyPy, ZipPy, Unladen Swallow, Pyston, etc. In fact many of these projects use research developed only over the last decade or two, which CL does not use, such as partial evaluation, partial escape analysis, tracing JITs, etc.

So we all know the research, and we know how to put it into practice to make both Ruby and Python run very efficiently. There's no question that Ruby and Python can benefit from this work, because it's already been done many times. What does not look tractable is cramming it all into the existing code bases of CPython or MRI.