HDDs will continue to be declared dead into the next decade, just as they have been for over a decade, meanwhile they are being enhanced, continued to be used in evolving roles.
SSD will continue to coexist with HDD, either as separate or converged HHDD’s. Where, where and how they are used will also continue to evolve. High IO (IOPS) or low latency activity will continue to move to some form of nand flash SSD (PCM around the corner), while storage capacity including some of which has been on tape stays on disk. Instead of more HDD capacity in a server, it moves to a SAN or NAS or to a cloud or service provider. This includes for backup/restore, BC, DR, archive and online reference or what some call active archives.