A new version of twisted is availble.
Incidentally, as mention https://twistedmatrix.com/trac/wiki/Downloads#IndividualProjectTarballs split packages aren't the prefered format.
This release contains minimal support for python3: http://labs.twistedmatrix.com/2013/01/twisted-python-3-and-you.html
If python3 support is added to the ebuild, then it should probably be masked by default, since the majority of it doesn't work yet.
Bumped. No py3 support.