The Track from my opinion is targeted for the Cloud services and cloud networking. As of the trend, the services are getting converged, and datacenter is becoming the connector for various sites.
The track will cover the datacenter networking, specifically the Nexus platform. The second section of the track covers the storage networking. Third part is the virtualization. Further details can be found in https://learningnetwork.cisco.com/docs/DOC-13992
I see this as an essential for datacenter networking engineers. Specially if they want to work, and evolve into the newer technology “the Cloud”.
I would end this entry with a great article on this topic: “With CCIE Data Center, can network engineers become data center gurus?“