librarything and Shelfari coverage......take off in social cataloguing?

Librarything had some good coverage in the New York Times called A Cozy Book Club, in a Virtual Reading Room.
And with Shelfari getting $1million dollars investment from amazon. I like the idea of both librarything and shelfari, i'm always worried there business plan may fall down when more people suffer social networking fatigue. I suppose they'll add more features then........