Go's Windows and GUI support is questionable at best. If anything, Go is a Ruby, Python, and server-side C++ killer. Go gives you the development iteration speed of an interpreted language with performance approaching C. Go is a reasonable compromise in the backend arena.
Not even close. Lack of generics, object orientation, GUI-based companion tools, and (most importantly) a large vendor behind the language will prevent it from breaking out of the “scripting” space and into the “enterprise” space.