Gee, I go away for a little bit and miss all the fun...
Personally, since the next versions of Pythonista and Editorial are going to involve some radical changes anyway, I'd vote for making them "Pythonista2" and "Editorial2", with Python 3.x (only), and keep the existing versions around in maintenance mode
I would disagree with this as I still believe a version of Pythonista that supports 2.7 should be publicly available and this strategy will mean that only those that already own Pythonista will be able to access a version that supports Python 2.7.
To be clear, by "maintenance mode" I wasn't suggesting pulling the current versions from the store, just not upgrading them beyond bugfixes. They both work fine on iOS 7 as is.
Short of "no Python 3.x ever", and given that both flavors can't run in the same executable, the remaining choices are either to switch both existing apps to Python 3.x at some point (leaving users with no choice), or to release new "v2" (or "v3", if you will) versions of the apps and keep the current (Python 2.x based) apps around, in which case Ole can either put extra work into keeping all four of the apps in sync, featurewise, or he can leave the current ones pretty much as-is (save for bugfixes) and concentrate new work and features on the Python 3.x versions going forward. I was voting for this latter case (and yes, I completely get that it's Ole's baby, this isn't a democracy, and we can only make suggestions / express preferences).
I was promoting the idea of doing the change at this point because (aside from "hey, more new toys for us"), Ole's recent work points towards releasing new versions of both apps simultaneously, with significant user-visible changes (sounds like Editorial's workflow entry has been "reimagined" because of the iPhone), and with Editorial going Universal.
If Ole doesn't hard-switch both apps (and all the users) over to Python 3.x at some point in the future, there will eventually need to be new Editorial3 / Pythonista3 apps, and casual users will want to see substantial user-visible changes when facing the prospect of paying for a brand new "edition" of an app (particularly on the Editorial side, since it presents to the casual user as "merely" a text editor - Pythonista users, on the other hand, will tend to see Python 3.x itself as a new major feature), and Ole's got those kind of changes in hand already, so it'd be a fitting time to make the jump.
And now I'll stop talking (sorry, I sometimes explain at length in cases where it looks like I'm arguing vigorously for or against something, when I'm actually just trying to clearly convey the precise "flavor" of my point - that's sort of what's going on here - sure, I'd like to see Python 3.x sooner vs. later, but what I'm most anxiously awaiting is the iPhone version of Editorial, so I'll be able to use the same text editor on both iPhone/iPad).