A view from above: The Mac Pro utilizes a giant triangular heat sink ("Thermal Core"), shared by the dual graphics cards and CPU.

Looks like the Mac Pro has taken some design pointers from the recent AirPort Extreme and Time Capsule bodies: a thin, vertical design with individual boards on separate sides.

We use our spudger to pry the graphics card data connectors from their sockets. This FCI Meg-Array connector is the same type used for the G4 & G5 PowerPC processor daughtercards, and looks to be a fully custom way of hooking up PCI-E, with many pins in a pressed-in connector.