The technology in question, such as it is, is absolutely off-the-wall crazy to my CMU-bred understanding of what programming languages are and ought to be. I seriously wonder what he intends to do about side-effects when it is baked into the language/runtime-environment that even if-branches that aren't taken are executed. I disagree with nearly every point in his manifesto, except for some very stubborn sympathy for "Text is a dead end" and "Visual languages are not the solution". The way in which names are inessential in the language I like a lot, but everything else is a frightful jumble. He keeps talking about avoiding complex abstractions like the plague, but subtext introduces a notion of aliasing and "variants" that seem to me just as bad, if not worse. I am very happy to cope with many fewer aliasing problems by programming in a functional language; I'd be afraid of moving to a language where not only are questions of identity central to using the language correctly, but where also the precise semantics of identity new and unfamiliar.
It reminds me that I've been meaning to compose a certain little list of words and phrases. The purpose of this list of words and phrases is that, when you are a person arguing with me about programming languages, I will be infinitely happier if you can manage to make your argument without using anything on the list. They are not forbidden, exactly, but. Infinitely happier.
For now, the list in my head is something like: "natural", "expressive", "elegant", "intuitive", "X is called Y for a reason", "most programmers", "typically".
(of course I'm not immune myself to using all and any of these sometimes)