Well, I really missed a trick here. I completely missed that this was happening.
This is a new idea for Java, but Microsoft has moved somewhat closer to this with their .NET runtimes and there is a project to do something vaguely similar with Python, as well. It makes sense in functional terms (though that determination is at the limits of my knowledge) though there is the problem of this sort of thing extending download time on less capacious network connections.
If you have an interest in network applications or web development this is definitely one to watch. It is possible some aspects of this will appear late in next year.