totally! By now we are on a very early stage (one URL = one author) but as the whole thing evolves and we are able to mark each piece of content properly that will have a lot of sense.
In a blog post for example, you would have the content of the post itself, the comments, the navigation bar, the sidebar, the footer, etc., so Google would be able to calculate the "importance" of that main piece of content based on:
- The author rank of author of that content
- The number of comments
- The author rank of the commenters
- The relationship between those commenters and the author of the post
- The relationship of the author with the topic
- The relationship of the commenters with the topic
- And so on... (along with all the other signals they take into account now).
And they would also be able to provide more specific info on SPYW. For example, if we perform a search and a blog post appears where one of our "friends" commented, we could see the result with a "your friend <x> and <y> other people commented on this post" with a preview of that comment. Even with ratings, if we search for a hotel or a product and things are marked up correctly, we could see a "your friend <x> rated this product with 4 stars".
IMHO, things will change, a lot, as Google needs to update the nowadays spammed link graph