I love Go, but it is a systems language (a C replacement), not a UI language. That's not even my opinion, that's how they market it.

Actually, Go would be great for GUI programming, precisely because it has a concurrency model that doesn't suck, and GUIs are almost always concurrent. Remember that Go's concurrency model is a descendant of CSP which Rob Pike first used in Squeak, a language designed exclusively for building GUIs: http://doc.cat-v.org/bell_labs/squeak/

I doubt that will happen but would love to see it