SOC Running Directly on Disk
The Marvell concept is interesting, but is a single-source, proprietary solution that would be difficult to find adoption as dual-sourcing is certainly required to have adoption move forward.
For Ceph, the better solution is Ceph running directly on the disk drive. Seagate Kinetic API can run with Ceph but also the SOC on the Kinetic drive could run Ceph OSDs on the HDD as well.
WD Labs previewed Ceph running on a 504 Ceph Node cluster in a single rack >4PB during OpenStack conference. Attaining speeds of ~ 90 MB/s per HDD! With only HDDs and TOR switches in the rack (no servers involved). The TCO/savings seems obvious.
That takes care of the latency and performance issue. As stated in the other comment, SOC running on the HDD would be the most cost-effective method due to volume as well. Flash drives could do similar - with 64-bit SOCs on each Flash/SSD/NVMe drive! You could then mix and match solid and rotating media in the rack to suit use cases and load.
The SAS/SATA connector is superior over RJ45 since it allows higher density EBOD Ethernet enclosures to utilize the passive SAS backplane to conduct power and Ethernet signals with the industry standard HDD connector.
The Micro-Server HDDs could now investigate hyper-converged at the drive level!! MapR or other analytics running on the drive w Ceph OSDs? many hyper-converged use cases could be easily imagined! This has the potential of being a cool, disruptive movement.