Pretty soon, I guess.
SanDisk declared their 6TB and 8TB SSDs would be available late next year (2016).
Both Intel and Toshiba said last March, a 10TB SSD would be available for manufacturing also next year.
And last August, Samsung unveiled a whooping 16TB SSD, the largest (so far) single capacity hard drive. The new drive is called the PM1633a.
Their one common denominator is they did not yet revealed their price.
So the question is, how much are you willing to pork out for one single storage unit? (one single point of failure.)
For me, it makes more sense to invest on say an 8TB capacity RAID system powered by 8 X 1TB SSD. Then you enjoy both worlds. Capacity and redundancy.
Not to start any RAID argument here, just saying..