A few years ago, we switched from Trac to Bugzilla. After doing this, we discovered there were some things we really missed about Trac. The first was a unified timeline so that we could see what was going on in the bug tracker. The second was a roadmap that showed us, for a given milestone, where we were at.
I coded up both of these and over the years have made some adjustments. I made the timeline script available a while back, but I don't think I ever made the roadmap script available.
The repository with both of these is at https://git.participatoryculture.org/bugzillascripts/.
They work with our Bugzilla 3.6 instance. I haven't tested either on other versions or other instances.
If you use either or both, send me an email about whether it works for you, bugs, comments, ...