It is with the addition of a better GPU.
Making high-performance, removable external PCI devices possible was one of the design goals for PCIe. PCIe is hotpluggable and can run about 20 feet over copper cable. Cabling and connector specifications
already exist. The real question is why laptop vendors don't offer a full 16x external PCIe connector for this, ahem,
express purpose.
The only problem here is his clunky implementation. That's forgivable since what he wants doesn't exist and I'm sure he doesn't have the luxury of designing and fabricating his own laptop. With proper vendor support, this is actually a brilliant solution to the laptop vs. desktop dilemma that more and more consumers face. Personally, I would probably not ever buy a desktop again if this existed.