As stated...Originally posted by bousozoku
SIMD is a generic term, Single Instruction Multiple Data. The SIMD part is VMX, the same name given it by Motorola and IBM did license Motorola's design although this doesn't mean that they're about to use it. They just need compatibility with it.
They most likely licensed the instruction set and the some of the characteristics of the Altivec Black Box Motorola is using, although internally IBMs implementation may be quite different.
Since Altivec is a mature instuction set used by many different PPC platforms, IBM using the Motorola Altivec instuction set isn't too outrageous.
If Motorola did kill the 7457-RM and beyond processors, there are quite a few VME and blade manufacturers that can jump over to IBMs 970. And a few Linux PPC board makers that'll jump on also (cough, an Amiga furball, cough).