Actually I use django.contrib.comments which has some improvements added in 1.0.1 version, such as RSS fixes and i18n, and in this version about 200 bugs was fixed. But it breaks support to some 0.96-style parameters.
Actualy I would pretty happy if you upgrade but if you not I can rewrite some small parts of code for compatibility, I've just started developing a site.
As for Python, the one real thing from newer versions I used to is exeptions with except and finally blocks in same try, but I can simply avoid it.