I'm also greedy for a python 3 version :-)
It's clear that python 3 is the future (and present) and python 2.7 is the past (and present).
At sometime the transition time will be almost over and everybody will use python 3, except for some legacy stuff.
Archlinux has python3 as default, fedora and ubuntu will follow next year.
Because we are in a transition time, a newbie needs to deal with this topic at the moment.
As long as he doesn't needs a library wich only is supported in python 2.7 it would be a bad idea to start a new project in python 2.7.
So I hope that after the big ios 7 update, python 3 is next for pythonista :-)
I don't mind to have two pythonista version in the appstore. A python newbie needs to be confronted with this version stuff, at the moment.
Or your could make an in-app purchase for python 3, and later on at some time you can switch to python 3 as the default a make python 2 an in app purchase.
In pythonista you could have to separate workspaces and environments one for python 2 and one for python 3.