Drobo B1200i
via TechCrunch
The Drobo B1200i is a 12-bay version of the Drobo FS featuring iSCSI interface.
drobo
Data Robotics DroboPro FS
via Engadget
The Data Robotics DroboPro FS is an 8-bay 3U design featuring a 1GHz processor, dual gigabit ethernet, and automatic offsite syncing.
Data Robotics Drobo FS
via TUAW
The Data Robotics Drobo FS features a dual core processor, with one core running the embedded proprietary OS and the other core running Linux. The unit also features five 3.5″ SATA storage bays and dual drive redundancy.
DroboElite
The DroboElite features 8 drive bays, dual gigabit Ethernet, dual-drive redundancy, and support up to 256 virtual drives.
Source: HotHardware
Drobo S
The Drobo S features 5 bays, dual-drive redundancy and eSATA connectivity. It also sports a faster processor compared to the standard Drobo model.
Source: HotHardware
Drobo Pro
The Drobo Pro features 8 drive capacity with dual Firewire 800, USB 2.0, and iSCSI. At the moment it allows for up to 16TB of storage and is able to be rack mountable.
Source: CrunchGear