I think it is a really nice idea jessicaetcetc but I think now is not the right time.
all the publicity on this will have scared off nobody - she would be a complete lunatic (which of course she isn't, not at all) to sue for libel now having seen the furore that it has caused. even she can work out that people calling it a potential test case for internet defamation law sounds bloody expensive, and frankly she is unlikely to win.
if she is nutty enough to press on, then organise a demo and masses of people from all over the place will attend. meanwhile, mumsnet should continue to dig their heels in, and nobody will quietly fade away.
unless of course, as I suggested, she is a nutter.
which she isn't.