The announcement describes the system:
At the core of the new system is a massively
parallel computer system comprised of 3,392 FX1
computing nodes. Compared to the existing system,
the new system delivers peak theoretical calculating
performance of 135 TFLOPS, approximately a 15-fold
increase, 100 TB of total memory, a roughly 30-fold
increase, and total storage of 11 petabytes (PB),
approximately a 16-fold increase.
The FX1, available only in Japan, appears to be targetted specifically at the HPC market -- a single CPU server node with 32GB of RAM, but only one hard disk, and sporting an InfiniBand HCA, designed to scale to thousands of nodes. Although, the need for small servers with excellent single-threaded performance may be reflected in the Ikkaku.
The datasheet on the FX1 contains some specs about the SPARC64-VII, especially the clock speed. The FX1 includes a SPARC64-VII with four cores running at 2.5GHz, compared to the two cores running at 2.1GHz to 2.4GHz in the SPARC64-VI which currently ships with the Sun Enterprise M-class servers.