Alexandre and I were talking on IRC today about what to do with bugs caused by packaging issues. Most of these are bugs in the packages provided by WineHQ.org and not by the distributions proper (who instead ship stable Wine versions). Consequently, users expect to file the bugs in our bug tracker since there's no where else for them to go.
However, non-packager Wine developers don't want to see these bugs, as they're frequently just noise and not their problem. But closing them invalid doesn't quite help, since otherwise the problem might not be fixed.
That's where the packaging component (or product) comes in - once an issue is deduced to be a packaging error (say, a missing build dep), then it can just be reassigned and the relevant packager auto-subscribed.
Thanks, Scott Ritchie