Hide me, hide me! 
I think that it's time to revisit the arguments for this again: the site is much bigger and full of wankers than it used to be, and there is a lot of unnecessary conflict. Given that civilian moderators have been discounted, and that the community team's workload is practically Dickensian, don't you think that anything which will reduce personal attacks and thus the need for deletions would be a good thing?
I understand that Justine is worried that threads "won't make sense", but given that a) people mostly talk shite anyway and fly off-topic (eg Larkers in the face of Po-some OPs etc); and b) the hide button would be individually activated by choice and not compulsory, I don't think this argument really holds water.
There are many posters mature enough to never need to shield themselves from the profoundly irritating, and some folk are naturally imbued with a zen-like calm in the face of fucknuggetry, but for the rest of us, please please please give us the option to simply never have to read the posts of people we know invariably get on our last nerve.
I am convinced that spats will reduce; people will participate more widely and constructively in threads, instead of having to hide them once their nemesis appears; goading will become much less sustained; and the bill to MNHQ for gin at weekends will be slashed to pre-2005 levels.
What's not to like?