I'm not strongly opposed to this enough to vote no, but it's something I would find a bit disconcerting to think about, and has the potential to stir up a fair amount of wank. Most obviously, notifications would be abused by allowing people to easily stalk someone particular in a community, for things like let's find fault with every single thing she says. Less obviously, it encourages cliqueishness, by making it easy for people to only look at posts that their friends care enough to comment and generally coordinate themselves to the exclusion of other people.

I don't think it would be good for DW's community, honestly. Too much potential for abuse, not enough benefit.