An article worth reading and thinking about is Gerald Seib's piece Senate Woes Flag Wider Disease in the Deb 15, 2010, Wall Street Journal. Seib argues that while the increasing use of the filibuster is certainly one of the proximal causes of the Senate's current dysfunction, the root cause lies much deeper in the increasing polarization of the parties, driven by several disparate circumstances - the 24 hour news cycle, the lack of social friendships across the aisle, the decline of moderate Democrats and Republicans in the Senate, etc.
Of course, at root, those moderates are gone because we the voters didn't elect them. Instead, under the influence of expensive paid advertising, talk show hosts, the rabid blogosphere, and TV we have all increasingly elected far right or far left "ideologically pure" Senators and Representatives. And when one of our Congressmen or Congresswomen have shown any moderate tendencies, any tendency to stray from ideological purity, they get attacked viciously BY THEIR OWN PARTY AND FOLLOWERS! So at root we the voting public are at fault. We the voting public are the reason there are so few moderates left in Congress.