I predict that some time in the next year we will see the release of a "Mac Pro Server" product that utilizes the same chassis and general design of the new Mac Pro but undergoes significant internal design changes to replace the dual high powered graphics cards with a second full-power CPU for up to 24 total cores (or perhaps more if we don't see this update until the next Intel architecture generation allowing for more than 12 cores per CPU), as well as more memory slots. I don't have any insider information but this is just a relatively straightforward and obvious prediction. Apple must continue to support its OS X Server features, which are a key feature to some enterprise customers, with appropriate hardware, and a single CPU, 4 DIMM slot, double graphics card workstation is outrageously unsuited to the server role. However, we know that the dual graphics cards are very demanding units so replacing them with another Xeon CPU and maybe also a much smaller discrete GPU (or else it could rely on integrated graphics) should not pose a problem from either a power supply or heat dissipation perspective. They just have to reconfigure the internal layout a little. Seeing as how they aren't going to bring back Xserve or anything else in a rack chassis, a Server-oriented version of the Mac Pro with a second Xeon and more DIMM slots is almost inevitable.