I'd argue that Twitter already provides the "best tweets people you follow read," thanks to Favoriting (Discover tab) and Retweeting (main timeline). I'm not sure that I believe Twitter can programmatically tell people what I think is "best" from my timeline.
As for Josh's desire for surfacing trends, it seems like we're talking about following topics rather than people. This may actually be a good way to a) onboard new users (don't worry about following individuals, Twitter curates lists of people that fit into trends, categories, etc.) and b) isolate real life events. For instance, it would've been great to follow the Hurricane Sandy topic (and have Twitter programmatically provide a feed of Sandy-related tweets that trend upward).