What I've decided, having used FriendFeed for a while, is that the direction everyone needs this to go is a standards-based feature of the feed-producing platforms themselves. Having to go to FriendFeed to see what my friends are doing in a site which should incorporate the other sites is akward and annoying.
I'm not ragging on FriendFeed. I like that they're tackling this. But signing up for Facebook, then Flickr, then signing up for FriendFeed and telling FriendFeed that I use Facebook and then Flickr and then adding the FriendFeed app to Facebook and not being able to do it to Flickr is just dumb. Hopefully FriendFeed or something like it can become a de-centralized value add of any serious social network, based on an open standard, while not losing the ability to import or fake friendships for the other 75% of users.
One day, I would like to add a friend on Twitter and have Twitter ask me if I'd also like to friend her on Facebook, Flickr and [insert x here], since we both use both services.