This is simply the product that needs to be able to support ongoing growth in the core. It is neither revolutionary nor in fact terribly new. Juniper t1600+TXmatrix is roughly the same class of router.
Big core routers have a service life of around 5 years and the CRS-1 was introduced in 2004.
The size and complexity of the forwarding table in these mainframe style distributed router platforms is at least as important as their throughput (and speed of the slot interconnects to a non-blocking fabric is the biggest part of that). and of course that's not the part that journalists have been covering since in layman's terms it's almost completely incomprehensible. These boxes are designed for 5-10 million routes spread across a number of VRF (virtual router and forwarding) instances which is going to have to last them until 2015 or so which is potentially a fairly iffy proposition.