IBM will basically be opening up the POWER architecture and allow third-parties now to make their own customizations and chips based upon POWER -- similar to how many companies are pushing out their own ARM Systems-on-a-Chip.
The companies joining IBM in the OpenPOWER Consortium include Google, Mellanox, NVIDIA and Tyan. In regards to NVIDIA's interest in POWER, they are wanting to integrate CUDA GPU and POWER together for some impressive high-performance computing (HPC) potential. Tyan is seeking to put out their own POWER motherboards.
IBM's press release notes, "The move makes POWER hardware and software available to open development for the first time as well as making POWER IP licensable to others, greatly expanding the ecosystem of innovators on the platform. The consortium will offer open-source POWER firmware, the software that controls basic chip functions. By doing this, IBM and the consortium can offer unprecedented customization in creating new styles of server hardware for a variety of computing workloads."