Lots of Trac plugins look promising. Unfortunately only a handful really delivers and even then some of them are not properly supported or maintained. They also tend to conflict sometimes.
I will not recommend anything for project management specifically but these are the ones which made our live so much easier:
- TagsPlugin - the most useful one, adds tags support
- BreadCrumbsNav - show previously visited pages, saves lots of time
- ShowPath - show the breadcrumbs path, useful if you have your pages named hierarchically
- CaseInsensitiveWiki - allows entering case-insensitive URLS
- Stratistics - show Wiki/SVN statistics
- WikiRename - allows page renaming (does not work well with the Tags)
0.10
- WebAdmin - pre-installed in 0.11 but before you need to get it separately
