Of course I don't think that. I meant by "ubiquitous" to imply the opposite. I fear we're talking past each other.
The risks of Google behaving like a Microsoft-style monopolist here are low because (a) they have no monopoly in browsers, VMs, or OSes to abuse, (b) their culture is the most hacker-driven of any large company, (c) their interests are aligned with what is good for the web, and (d) the industry has changed since the bad old days.
Given this, and because the potential value of this project is so high, I'm willing to give them a chance.
Since making my original post, I've read a bit more about Bracha and Newspeak. Assume for the time being that Dart is an evolution of this work. We're talking about a fast, small, even-more-dynamic Smalltalk augmented with ideas from Self and E, designed for the web and multicore. That's mind-blowing. Now throw in the implementation prowess of a Bak and the institutional support of a Google, and we're talking about something potentially game-changing. To judge by their track records (e.g. the Resilient embedded Smalltalk that Bak worked on), these guys are out to correct not only the mistakes of Javascript but of Java as well. Historic stuff, which they have as good a shot at pulling off as anybody ever has.
I admit the odds are against it turning out so well. But this is the rare case where at least some optimism is well-grounded. If what they release does turn out to be an attempt at the above, it will be exciting.