Comment 2 for bug 444579

It looks like a transition issue to me.
In aptitude, the package is indeed in the "Obsolete" section.
Having a look at the package description in aptitude, the "Versions" section reads:

      --\ Versions of python-zopeinterface (2)
       i 3.4.0-0ubuntu3
       p python-zope.interface 3.5.2-1

So the new version is listed, but its name is different from the old one.
The obsolete package name is "python-zopeinterface" while the new one is "python-zope.interface".
I should add that the manual selection of the new package does not raise any issue like breaking dependencies and allows a manually forced transition.

Would a meta-package be of any help to make the transition automatic?
Apropos meta-package, the changelog of 3.5.1-2 mentions the "removal of python-zopeinterface metapackage as it is not needed". Is this the culprit?