It certainly looks interesting, but nobody's doing that so far as I know. I'm having trouble figuring out how the discussion is "global" when I've supposedly got full control.
I'm sure that if someone creates such a plugin, we'd add it to the repository.
Friendfeed is an Aggregator for all Webb2pointO Services to collect Data from it in a kind of LIFESTREAM at one place. There people can comment and like things and this data i would like to see at my blog, so everyone can talk about my posts at friendfeed.