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.
I am not really personally bothered by Python 3 being incompatible (with that one Jython exception that I already mentioned). But I would like to point out the comment https://news.ycombinator.com/item?id=13146127, I think you're the one who is wrong here.
> It's more likely that Python will suffer from people moving to other languages
Unlikely. Rails are probably going out of fashion. Javascript is a terrible language, which only saving grace is a decent support in browsers. I am not sure for what other reason, choosing a language today, I would choose Javascript over Python 3.
So people moving from Python 2 are most likely to end up with Python 3, I don't really see compelling alternative for them (unless they are going to something more functional like Clojure or Haskell or Scala, but that's entirely different discussion; for example I like Python a lot but I feel pure functional is where the future is, I find the imperative programming quite annoying these days, I would prefer Haskell, but frankly, I am not nearly as productive in it as I am in Python, because Python's focus on usability is very hard to match by any language).
On the other hand, I think Python 3 will actually gain in science and data analysis thanks to things like @ operator for matrix multiplication.