Also be aware of the following:
There is currently no memcached library for Py3k. https://github.com/lericson/pylibmc/issues#issue/21
[edit: If you use the uWSGI appserver with nginx or cherokee to deploy, I believe it will have cacheing for Py3k in its .97 release next month]
One of the problems is python.org has been emphasizing a Python2to3 without a Python3to2 converter. The ideal situation would be library, framework and module developers write in Python 3 and release a compatibility Python2 version via an automated converter, rather than the other way around. Otherwise they will be forced to do primary development in Python2 and not have the resources to maintain a separate Py3 branch.
Link to Python3to2 repository: https://bitbucket.org/amentajo/lib3to2/