I've been thinking through my past complaints about Bugzilla, such as my post about bug summaries and my post about having separate categories of content in Bugzilla, and various poor interactions I've had with others in Bugzilla (such as having missed key details in comment 27 and later in comment 14 when discussing Bug 823989), and I've come to the conclusion that I was previously misunderstanding the real problem I was having with Bugzilla.
The biggest problem I have dealing with bugs is that they require reading through a long stream of comments -- the entire history of the bug -- in order to figure out what the current state is. I end up trying to skim these comments in order to find the ones that are still relevant; this both wastes time when I'm reading the ones that aren't relevant and causes worse problems when I miss ones that are relevant.
I'm coming to the conclusion that the fundamental problem with Bugzilla, and with many other bug systems, is that they make the history way too important. If I want to fix a bug where the cause of the regression is known down to the changeset, I no longer need the fifteen comments that led to reducing that regression range; I just need the link to the changeset. If the bug has a simple, reduced testcase, I don't need the ten comments that led to figuring out which part of the code of www.economist.com is relevant; I just need the testcase.
I want my bug system's primary display of a bug report to show me the current state of the bug report, not its history. The history should still be accessible, just like the history of code is accessible in a version control system. The stream of comments should be replaced by a description field, which should be edited over time to describe what is currently known and what needs to be investigated.