Why I was wrong about Quora as a blogging service
scobleizer.com
scobleizer.com
Related discussion: http://www.quora.com/How-can-Robert-Scoble-modify-his-writin...
It seems like Quora's business plan was (1) get lots of users and then (2) think of some way to preserve quality. I hope they can flesh out the second part before everyone leaves again.
Also, Quora provides "Posts", which are not associated with Questions. They are much-more blog-like (and the main criticism of Scoble's answer was that it should have been a a post).