jangly, you're not dreaming: there was a discussion about like buttons on another thread. At the risk of boring everyone, this is (roughly) what we said there:
Sorry, realise this has come up before. We've thought long and hard about it and tried to draw on the Mumsnet experience. The main reasons we're not so keen (we don't like likes!) are that having a like button doesn't encourage conversation, that it can lead to hierarchies, with people competing for likes, and that it encourages cliqueyness (I'll like you if you like me). Now, we realise that gransnetters aren't like that with their liking (OK, OK, enough liking) and that sometimes people just want to signal appreciation, but our starting point is always what makes this as open and democratic, free-form and dynamic a forum as it can possibly be?
Tell us if we're wrong. Well, you will, obviously. Equally, tell us if you like.