USB C connector Alternate Mode can be used to carry PCIe signals (without Thunderbolt). Switching GPUs is a well solved problem for nVidia, they call it Optimus. By now this is a technically solved problem, no problems.
>By now this is a technically solved problem, no problems.
Is it? We're not talking about load balancing GPUs - we're talking about a GPU just disappearing underneath you (like when the user picks up the Switch), while maintaining context and dynamically lowering quality - I can't imagine that being a trivial problem.
But that's not the major issue here. Nintendo is going to have to sell this thing for under $400. A mid-market smart-phone costs that much. Shipping a dock with a high performance GPU along with the actual portable isn't going to happen.
I don't think with the nVidia blog posts and the pictures of the dock that they're hiding a more powerful GPU in the dock. If it were I'd expect a larger dock to provide more cooling to the docked GPU and some mention of 2 GPUs or GPU switching in the nVidia blog post about the Switch.
