There is a new CS-MARS Datasheet on Cisco.com, that covers what is termed Gen1 and Gen2 MARS appliances running Cisco Security Monitoring, Analysis, and Response System 4.2.x/5.2.x
This datasheet gives us some more info on the new Gen2 appliances..
And also the new Gen2 Global Controller...
Quote "The 4.2.x release will continue to support the MARS-20R, MARS-20, MARS-50, MARS-100e, MARS-100, MARS-200, MARS-GCm, MARS-GC appliances. The 5.2.x release will support features on new appliance models MARS-110R, MARS-110, MARS-210, MARS-GC2. There will be significant feature parity across the two releases. Although appliance differences may make complete feature parity impossible, it is the goal of the product team to provide near perfect feature parity across all MARS appliances."