It's an interesting issue. Back compatibility was broken with 3.x, which is always a risky move. Even Bill F*ng Gates was reluctant to break back compatibility, and he basically ruled the world (for about 20 minutes or so, but still).
Moreover, you get a lot of the good stuff with 2.7. Along with more library support. So the smart decision is to code your project 2.7, even though the best thing for Pythonistan would be for us all to voluntarily migrate to 3.x. At least that's my read on it. Feel free to flame if I'm out of my depth here, it wouldn't be the first time. -- https://mail.python.org/mailman/listinfo/python-list
