More languages should have a facility for keeping track of units and doing conversions, regardless of whether it's done in the type system or at runtime.
Making this a part of the type system seems a little strange to me. Obviously it's nice to get warnings at compile-time or in the IDE. But I keep trying to imagine how you might make a feature like this useful as a parameter to strings, or a user-defined type, and with functions other than the arithmetic operators.
Why are the code samples in images? I guess because they are intended to be screenshots of the IDE, but it sure makes them look crappy if you have the page zoomed.
I assume to show the type inference popups of Visual Studio. A better choice would have been to use the CopySourceAsHtml add-in and only capture the popups as images.
If they will fully optimize non-mutable structures and functions across processors I think it's a game-changer for Microsoft. But having said that, it might be five years before all the pieces come together.
In the past 3 or 4 years, Microsoft has really changed its stances on a lot of things in terms of languages. Between the DLR and F#, it certainly makes me mind working on .Net a little less.
I do wish Rich would resume support of Clojure on .Net, but I understand why he chose to focus on the JVM alone.
Making this a part of the type system seems a little strange to me. Obviously it's nice to get warnings at compile-time or in the IDE. But I keep trying to imagine how you might make a feature like this useful as a parameter to strings, or a user-defined type, and with functions other than the arithmetic operators.