Supposedly, several manufacturers, such as Seagate, are expected to launch their own 5-Tb hard drives, and although they had not yet made any announcements about it so far, one of the first to bring these models to the market will be Toshiba with their MG04SCA Series, which will arrive within a few weeks but, for now, only for the business market.
We say the business environment since its interface is not SATA but SAS, understandable for a MTTF of 1.2 million hours and 128 MB of cache. However, is a nice start, and Toshiba (and other manufacturers) will surely have no problem releasing these disks with SATA interface. Traditionally, users often get these new devices a few months later after the business market gets them. Certainly with the 5-Tb disks, Toshiba will sell 2, 3 and 4-Tb models, some of them with SATA interfaces.
What is clear is that the market for mechanical hard drives must somehow evolve, as these devices have been stuck in regards to speed and capacity for quite some time, and SSD are growing at an alarming rate.
Yes, Toshiba has not given information on dates and price, they have simply said it will be available "in the coming weeks."