[UPDATED]
Mainly five things:

Feedback from users
Personal Messaging System
Pagination among the forum listings and topic pages (there is already back-end code to control all this, I just need to write the widget to place in the UI (view).
"Reply w/Quote" link on each topic (similar to the "reply to author" link in web2py groups.
internationalization update - All strings in pyForum are i18n-ready (there is just no language definition file available yet), the ability to automatically change the default language to the user's preferences is something that still needs to be tested thoroughly.

The system, even in its current state is useable for the most part. This means that you may begin to add your categories and forums within them, you'll have to spend some time configuring these, as you fine-tune its properties (i.e. who can view a category, who can, in addition to view a category's forums, add topics in it, or reply, or a combination of them, also the "system properties" has at least 17 system-wise configuration parameters for you to fine-tune as well).

-- sb