Bit late to ask this but....
I'm wondering if there was ever a conceptual idea to establish some sort of volunteer based team whose aim was to track down and find solutions for the backlog of bugs that has built up over time. Now I realize that The Toady One doesn't necessarily need or want help, but I am seeing this from a less then direct angle. The plan would be for a group of volunteers who are familiar with at least parts of the game's code to try and pinpoint what is causing certain bugs, attempt to solve it, and then provide a report detailing what was changed and where in the code. Other volunteers, ideally the more experienced, would go over the report and try to determine if said solution is "safe" and would not cause errors elsewhere in the game, and should they feel confident in a solution they'd publish it. Toady himself could then choose whether or not to act on it, I definitely will not rule out cases where a found solution to a bug might cause problems in later versions and so may be found undesirable, but DF players would also have a choice to act on it.
Mind something like this could already exist in some form and I'm just not aware or failing to recognize them.