I think the biggest loser as a result of Netflix charging separately for streaming and DVD by mail isn’t going to be consumers or Netflix. If people really stop having DVDs delivered to their homes, the real victim is going to be the U.S. Postal Service.
Outside of Netflix, the only reason I need the USPS is to deliver thank you cards for kids’ birthday parties. I think I could deal with hand delivering those a couple times a year or sending them over long distances through FedEX.