Our Apple sources are back at it again, telling us that we should expect with absolute certainty that Apple will launch the new Mac Pro refresh at Mac World in January and that it will feature the Intel Nehalem architecture.

Our sources tell us that we should expect it to use either the Xeon 5500 series or the Xeon 3500 series processors that use the Nehalem architecture. The 5500 series is expected to top out at 3.2GHz and it is expected to deliver a near 30 percent clock for clock performance increase over the current Xeon CPUs at the same clock speed.

While it is still unknown which CPUs Apple has selected to use from Intel in the Mac Pro, we do expect it to be a welcomed upgrade and be able to deliver some exceptional performance. However, the cost, as most are aware, will not be cheap.