Well here's my tuppence worth. Although I have been a member since 2006 I have only recently started posting, I was a member of another site where the community was a group of mums whose babies were born the same month as yours. There wasn't the same huge variety of topics on that board, but I got a lot of support from it when I was pg and when my ds was small, because of my tit xp's behaviour. But he eventually worked out my username and read all my posts, it was awful as I had posted lots of things about him which were personal and there were lots of not-very-nice remarks about him (all justified of course!)
So I had to leave that site, with regret, because I had a back story, which was recognisable to him, even if I re-registered or namechanged.
With Mumsnet I am starting from a different place. I haven't needed the same kind of support (although there are ongoing issues with xp some of which I have posted about).
I have taken on board all the views here and of course we all know that the internet is a global village type thingy. But I think my main annoyance is that the DM is going to use our stories, our hurts, our experiences, without MNHQ's actual approval, and without much regard for the trouble it might cause to individuals. And of course the DM is a hate-fuelled bastion of nastiness.
I'm hoping people won't leave and that things blow over, but I will feel more cautious about what I post. And I will think back to the days of ds's babyhood when I was so desperate for help that I blurted out details of my personal life without thinking that the site was Google-able, or might end up in a tabloid. I needed help, not a namecheck for the nation's amusement.
I do appreciate Justine being honest though, and keeping us informed. It makes the whole thing easier to bear, in some funny way.