As a real estate broker, I think the major problem isn't Zillow, Trulia, or any other repackager of information. The problem is the MLS. There is still one source/database of legit listings that is bought into by every other broker. Other site (ForSaleByOwner, etc) do not appear legit and nobody trusts a listing put there.

Democratizing the listing information is where disruption needs to happen. What do you think about me as a broker charging a small fee ($100-$200) to post your listing to the MLS, managing in/out calls, but letting the Seller keep the vast majority of the commission and letting a lawyer/broker service to handle the close/escrow process. Selling a home shouldn't be wasted on 15k to a broker who doesn't do anything. (Yes I realize CA has some laws that would make this tricky)

Another idea: How about having homeowners list their properties on a reverse-bidding listing site, where brokers bid for the listing in exchange for the lowest commission? Ideas?