(disclaimer: My opinion on Go is based on my own limited experience from writing a few private projects using OpenGL.)

Go seems like an exercise in frustration to me at the moment for anything GUI or low-level OS-related.

Many GUI libraries use an object model that's difficult to map onto Go's heavily restricted interfaces, especially with a lack of generics.

In addition, interacting with popular libraries (such as libsdl or even OpenGL) that use thread-local variables (TLS) means using ugly workarounds like this one:

http://code.google.com/p/go-wiki/wiki/LockOSThread

So I think it really comes back to the "right tool for the right job." For most command-line utilities, and for anything networking-related, Go would be my first choice.

But for anything that needs a modern GUI toolkit and uses OpenGL, it would be difficult for me to justify.

Again, I love the model Go provides for programs and packages purely written in Go; it's only when interfacing with system-level components that I get cranky.

Go on Android would be great, but Google used Java in the first place so that they could leverage all the Java devs in the world to build Android apps.

Go might be a much better choice from a pure dev standpoint, but from a getting everyone to build apps standpoint, it's a fail in the short/middle term.

I didn't say get everyone to build apps. It would simply be another option. App development is getting more competitive, of course, so people that want to stand out might need to move to Go to gain an edge. Plus, I image that a Go environment might provide a better interactive development cycle.

Yeah totally. I'm with you there. It would be great and I hope they do it.

I'm not so sure. There's no lack of iOS developers, and most of them are using Objective-C...

NDK on Android is native (C++/C) and it's there to boost performance and avoid GC in game loops. I've seen too many devs discussing how to mitigate the effects of GC in games to consider Go to be a worthy upgrade at this point in it's development, the NDK would probably still be needed...

Go has a GC so still not sure that would help. You'd have to benchmark it though, it might not matter.