I see no future for Python be that 2 or 3. It's not great at anything, but projects a veneer of friendliness (that one should quickly outgrow) on top of a pile of bad implementation decisions and terrible design.
Its popularity is based on superficial attributes rather than solid foundations. Eventually, the entire ecosystem will collapse and the masses will flood to the next attractor.
Go is interesting, but really a different (and perhaps smaller) use case. What, for instance, I do in Python? That little one-off script that converts one thing to another or calculates something - I am not sure why I would even bother thinking about Go.
I have no doubt that at some point, Python will be replaced by something. But I don't think it will be any of the languages that are currently in widespread use. Heck, C is also not based on solid foundations (I mean like type theory or something), and it wasn't fully replaced yet.
C is based on the solidest possible foundation: the actual hardware CPU.