Apple recently made a bid for PA Semi, a semiconductor design company specializing in high performance, low power processors. The company is a licensee of IBMs POWER architecture, previously used by Apple as the PowerPC chip line, leading some to believe that Apple may be moving its Mac line back to PowerPC chips.
The truth however is less dramatic. Apple may be working on differentiating its hardware lineup by including discrete coprocessors for tasks such as video encoding, graphics design acceleration, and other high performance applications.
This sort of acceleration has been possible for a while now with the OS X Acceleration Framework, which takes advantage of whatever hardware is available on a machine, like SSE or Altivec instructions, graphics processors such as the Intel GMA or Nvidia chips, and in the future, dedicated coprocessors.