Ran across Google's Dart programming language today with an announcement they made.
Those design goals are interesting. Hrmm. Only Node.js and GWT target client and server? How about Fantom and haXe? I suspect there are many more. I'm just mentioning ones that I'm most familiar with. I haven't gone on a link search.
I think Fantom is especially aligned with many of the goals of Dart. But making one's own language is fun (and time-consuming). Been there before myself. Maybe again someday. In addition to having been around longer, Fantom has the benefit of the compiler being implemented in Fantom. Dart seems not to be self-hosted yet. Maybe they'll get there someday.
Meanwhile, if Dart sounds interesting to you, I'd recommend taking a look at Fantom first. It even has Eclipse and NetBeans plugins already.
Update: It seems Google Dart has some Eclipse IDE stuff in the works, but I'm having trouble finding detailed discussions on it.
Update 2: I also missed the native VM. With the compiler in Java, I wrongly assumed the whole back end thing was Java-based despite their discussion of a VM for Dart.
Update 3: It seems Gilad Bracha's involved, and the type system is more dynamically-focused than I thought at first glance. I'm concerned that making types too optional will make code tooling weaker, but maybe they have clever tricks planned for performance and tooling. (I mean, V8's pretty good at performance with little-to-no static type information at all.) On the happy side, generics are reified.