When deciding whether you are getting involved in a fairly big open source project in order to contribute to its code base, how significant are the project's issue tracking facilities (i.e. tracking of bugs & feature requests) for your decision to contribute or not?
There are still many non-trivial (huge code base) open source projects out there, that don't formally do issue tracking - and while some contributors may indeed still do this privately in the form of miscellaneous "ToDo" lists, I have personally found the lack of availability and established use of issue tracking to be a fairly reliable indicator for a lack of organization, structure and overall project coordination.
What are other people thinking?
I would say it would be a fairly significant factor.
An open issue tracking system is one component of what I would call having an 'open development process' - where anybody who is so interested can see the developers' decisions as they are being made, and contribute to the discussion.
Some projects don't really have an open issue tracking system (or a good one) but still have publicly visible discussion lists, maybe an IRC channel where there are always people on, maybe a forum/bulletin board, etc. In my opinion such projects are still fairly attractive in terms of contributing to them.