I think it'd be great if they used features like thumbs up / thumbs down or just thumbs up that we can "vote/support" other people's comments on people's threads as would prevent everyone repeating the same thing just to reiterate to the OP that there's lots of us thinking the same thing.
Also, perhaps a way to reply to a specific comment by having a reply which will box quote the person's comment and can write reply underneath it rather than bother with @ user name.
Not sure if mumsnet has a feedback contact so thought I'd post here and see what people think? A lot of forums have these features and I think it would be a great addition for this one.