Python 3 support in Django 1.5 is experimental. I would wait until Django 1.6 is launched or there are well-known, well-working examples of Python 3 implementations of Django on high traffic sites.
FWIW, that "experimental" label doesn't quite mean that 1.5 isn't ready for prime-time; it's more about setting community expectations. Please see my reply elsewhere in this thread (https://news.ycombinator.com/item?id=5289006) for more details.
ETA: That said, the advice to stick to Py2 right now is probably good. There's still some key missing 3rd party packages, so you'll generally be happier as a Py2 user right now.
ETA: That said, the advice to stick to Py2 right now is probably good. There's still some key missing 3rd party packages, so you'll generally be happier as a Py2 user right now.