Sure nvidia could build a traditional co-processor card(just like in the old SBUS days) but what are the chance of apple releasing hardware with that kind of ex

Sure nvidia could build a traditional co-processor card(just like in the old SBUS days) but what are the chance of apple releasing hardware with that kind of extendability after going all in on the IOSification of the mac?, even thunderbolt(which is a much lower level bus then USB3) did not support the same kind of performance as a proper PCIe slot. And even if you could most of the software in question is composed of countless components some of whom predates the mac itself and porting that to support anthing but the traditional big core CPU platform is not a trival thing to do, which is why the Xeon powered workstations and servers still exists and why manycore designs only really work in the supercomputer space. You could argue that the workstation itself is a dead concept and that the future is "cloud" with html5 frontends even for video and CAD workloads* which is something autocad and adobe is likely working on as a long term strategy, but in the short term they need the workstation that post Jobs apple don't appear to to have any interest in building.