I'm ok with the deprecations.

Regarding the cElementTree module, this is a bit problematic. The idiomatic import has lost its use in Py2.5 when ET and cET were added to the stdlib, so code that was written for Py2.5 or later (e.g. because it uses generators) might no longer have that cascade. On the other hand, issuing a warning for the module would also hit this import cascade, even though the code would work just fine without cElementTree. One argument speaks for deprecation, the other for removal.

However, cElementTree is redundant now, so it should be removed eventually. And since that removal would break some code anyway, I'd be ok with just removing it without prior import warnings. People can then decide whether they want to fix their code by adding the well-known import cascade (and not get annoying warnings for it) or by switching entirely to plain ET and not looking back.