The MemShrink effort can also include leaks and quasi-leaks in its jurisdiction, even if areweslimyet.com doesn't demonstrate them.
In terms of tracking bugs, now that we're on a 3 month release cycle, I like the idea of having one meta-bug tracking all memory use reductions for the next release. I personally find meta-bugs like this to be quite useful so long as they have a clear end-point. So I opened [https://bugzilla.mozilla.org/show_bug.cgi?id=640452 bug 640452] for leaks in Firefox 5 and and [https://bugzilla.mozilla.org/show_bug.cgi?id=640457 bug 640457] for other memory use reductions in Firefox 5.