Speaking of Go's chance to be a "major" language, let's look at it from a historical perspective.
Right now, Google has some of the best intellectual capital in software engineering among all companies on earth. Their reputation is good enough to hype fucking COBOL as the Next Big Thing (tm) and people will still drink their Kool-Aid. They have a prime opportunity to revolutionize the current sorry state of software engineering. And now that they've decided to release a programming language, I feel that they are responsible to software engineers and computer scientists everywhere for making it COUNT.
This is why I am so disappointed with Go. Reading through the specification gives one a sense of deja-vu. All the stuff in there has been around for decades, and there are features NOT there that should be given that it's 2009. In fact, Go the language could have been invented circa 1989 by a CS graduate student and nobody would have batted an eye.
Google, with their not inconsiderable political sway, could have taken 40 years of research and made something AMAZING, and that language would have as much buzz surrounding it as Go does right now, even if it looked like it came from the highest ivory tower, simply because IT WAS DESIGNED BY FREAKING ROB PIKE AND KEN THOMPSON. No other people had that opportunity. Sure, one could put one's creation on the Internet and hope for the best, and it's worked small miracles for Haskell, Clojure, Factor, etc.. But reality dictates that these languages, no matter how inherently well designed they are, will never even touch the popularity of the major players.
Instead, we get a language that is only incrementally better than C, Java, and C++, which, I'm going to say straight, isn't much of an accomplishment at all. Ignoring syntax, here's what Go should have, at a MINIMUM:
Full type inference;
Parametric polymorphism, a.k.a. generics;
An effects system;
A macro system;
Type operators;
Exception handling or, even better, continuations;
NO null/nil construct. Seriously, that shit's not necessary in this day and age.
A few of these require a little runtime overhead, but like
>>84 said, if you really need that much speed, just go back to C. Hell, Go's already got GC and virtual methods. A little bit extra is just a drop in the bucket. To be fair, I like their inclusion of first-class functions, interfaces (which I feel are even better than Haskell's type classes), and CSP, but it's not enough. If they had managed just to eliminate null, I'd be all over this language, but alas, they failed.