Will the future belong to 2.5" hard drives?

During Computex, Fujitsu demonstrated a 10 TB server based on fifty 200 GB 2.5" drives.

Even with redundancy it has 8 TB of free space, the 2 TB lost being used for the parity check.
The power consumption of this server is less than 80W, which is a lot lower than the equivalent with 3.5" drives.
The only hitch is that it is based off of 4200 rpm drives.
So there will be a high data rate, but poor access times.
If 2.5" drives can gain in performance, obtaining 10,000 rpm, perhaps one day it will be a viable replacement for 3.5" drives in servers.