Well, as far as I can tell from the descriptions, this technique is at least similar to some of the JIT technologies (which is why I said it wasn't quite as new and revolutionary as they make it sound -- it's just novel to incorporate it into an "interpreted" language).

Not sure why you think of JIT as being out of vogue, though -- far as I know, it's faded into the woodwork simply because it's universal at this point. Are there are major IL-based environments that *don't* have JIT baked into them? My understanding was that at least Java/JVM and C#/.NET (the overwhelming favorites in the IL space) do so pretty deeply...