Redfin with its smaller cut of RE transactions on the seller side combined with the ability to circumvent MLS with it's own listing system could be the begining of the end for agents.
While I don't disagree with you, Redfin has been in business since 2004. 13 years is a long time to take to kill off realtors.
I'm in the process of selling my place and I'm using a realtor (who nearly matched Redfin's seller commission rate). The Redfin agent I first spoke to proposed a generic, templatized method to sell my property - list on N realtor sites, email my contacts, take nice pics - while the realtor I went with lives two doors down from me, knew the quirks of the HOA, had working knowledge of what potential buyers were looking for in my community based on recent deals he had been part of.
I agree. Realtors won't get killed- they'll just have their commissions reduced. I've bought a house through Redfin which was easy enough, but used an agent who agreed to Redfin level fees, but was much more knowledgeable and better at selling my house. From dressing up the house, doing open houses to following up with buyers, to negotiating. Redfin couldn't match him with their inexperienced agents/helpers, high volume and cookie cutter methods that are more suited to hot real estate markets where there's not much for realtors to do.