There was a bitchmeme going around. Scoble, Winer got into the act...
Scoble gets a part of right - we don't really have that much control, but Winer hits on what I think is important: There are already solutions for this (Atom Threading Extensions, RFC 4685, and RSS Comments feature). We can't control what people do with our syndicated content, but we can make it easy for tools to auto-discover the conversation specific to a given blog post.
I've made available a 'whole blog feed' and a 'per thread' feed on each post, but I'm really glad that WordPress 2.5 enabled the Atom Threading Extension 'replies' relation by default.