No, they need to stop living in PC's
Home PC users are creating and obtaining vast amounts of data through photos and videos that need somewhere to live. Broadband infrastructure is going to be in a speed rut for some time to come yet. The disk manufacturers need to get out the shadows and start producing very, very simple appliances that can be accessed by WiFi in seconds and back themselves up totally painlessly. But yeah, long term I think they can wave bye bye to most of their markets.