It's funny to me that Facebook responds to Twitter as they do. As Leena Rao points out over at TechCrunch, Facebook is still light-years ahead of Twitter. There's even some evidence that Twitter could be reaching a saturation point (difficult to determine on pageviews alone, of course).
Of course, it's not surprising that the mammoth of social media would take a page from the playbook of the mammoth search engine. After all, there are so many ex-Googlers now working for the social network (including the founders of FriendFeed). Google just can't seem to sit still when their underdog opponents make an announcement. They're always ready with things to update, even though some of them seem less than ready for primetime.
Facebook at least is not making that mistake. But the reminder of their spam fighting feature still reeks of a little too much "Me too!"