I used wxPython many, many years ago on a foolish project. I am sure it has matured.

But as always, I turn to PEP 20, in particular "There should be one-- and preferably only one --obvious way to do it." Batteries ought to be included. I'm hardly a language designer, but more and more I care less about things like syntax and such, and more about having as much as possible already built out, so I can focus on the particulars of a problem, rather than having to endure a "evaluate a bunch of alternatives" phase for each little thing.

It's a tall order, and a growing one, but I think whatever the next big language is, it will have that kind of focus.