Yes, it's coming.
As I've teased a bit earlier on Twitter, I'm working on a version of Pythonista that is based on Python 3.5.1 instead of the current 2.7.5. I've made pretty good progress recently, and the app is already in a completely usable state with most custom and third-party modules working.
Here's the most important part:
Lastly, this will be a separate app, or "paid upgrade" if you will. This is, by the way, one of the reasons I did not charge for the 2.0 update. It'll co-exist with Pythonista 2.x for a while because there are still valid reasons to prefer Python 2.7, and I don't want to force people to upgrade to a version that is not backwards-compatible.
Free stuff is great. But do you know what's better? Apps like Pythonista existing. This is what I like to call an insta-buy.