The Cell is a multicore CPU, made up of a 64-bit Power processor core and multiple synergistic processor cores. These cores are capable of massive floating point processing. The chips are capable of supporting multiple operating systems at the same time, and boast a substantial bus bandwidth to and from main memory. The Cell is implemented in 90 nanometre (nm) silicon-on-insulator (SOI) technology, and is optimized for compute-intensive workloads and broadband rich media applications, making it ideal for powering computer entertainment. More here.
"IBM, Sony Corporation, Sony Computer Entertainment Inc. (Sony Corporation and Sony Computer Entertainment Inc. collectively referred to as Sony Group) and Toshiba Corporation today unveiled for the first time some of the key concepts of the highly-anticipated advanced microprocessor, code-named Cell, they are jointly developing for next-generation computing applications, as well as digital consumer electronics."