What I would like to see is a language that is much more succinct, less bound in grammar rules/syntax but also less irregularities and ambiguities. English could evolve into this. Latin could have too but currently it is dead. Change happens.
But again, what language? We are not talking about computer languages. This is not a theoretical exercise in an ideal software world where you can start all over again. It's going to be one of the mainstream languages. Which one? Russian? Chinese?
Yes, currently Chinese is the main alternative with the most population and has some of the features I mentioned. It is also great for business with many people learning it to attract some of the chinese money floating around and lots of foreigners there to make their fortunes. But just a couple of decades ago it was russian. A major war between the US and China and it might be Hindi next. Never safe to predict the future.