To stay relevant I think they would have to support a dual-cpu configuration, and offer Tesla and Xeon Phi cards as options. High end RAM and disk setups would

To stay relevant I think they would have to support a dual-cpu configuration, and offer Tesla and Xeon Phi cards as options. High end RAM and disk setups would still be difficult to support in the current form factor though. I'd love to see someone start building modular, rackable, workstations resembling the Cray CX1. Unfortunately Apple is moving away from scientific workloads in general.