Short version is that it is a custom board into which you can plug multiple RPi compute modules (and now some Jetson modules) to create a miniature version of a blade server system; this board is the backplane of that compute module blade system. Use it to create your own edge cluster system I guess; it does not seem particularly useful beyond being a neat curiosity when you put RPi CMs into it, but as a GPU/CUDA node filled with Jetson modules there is some interesting possibility there for people looking for a cheap local cluster for training ML models.
4x Jetson nano would cost $240, the Turing board will probably cost around $100 (it looks like they haven't decided yet) and you get 1,88 tflops; you can add 50 bucks and get GTX 1060 with 4.4 tflops and you can play games.
Not sure that's quite a fair comparison, because you'll need quite a bit more hardware to use the GTX 1060, and I think that the Turing board + Jetson setup would be all-inclusive (except a power supply and chassis, I suppose)?
