The press release[1] says it's using NVIDIA's Grace CPU[1], as well as this:
MediaTek, a market leader in Arm-based SoC designs, collaborated on the design of GB10, contributing to its best-in-class power efficiency, performance and connectivity.
I assume that means USB and such peripherals is MediaTek IP, while the Blackwell GPU and Grace CPU is entirely NVIDIA IP.
That said, NVIDIA hasn't been super-great with the Jetson series, so yeah, will be interesting to see what kind of upstream support this gets.
I'm bracing for a whole new era of unsufferable binary blobs for Linux users, and my condolences if you have a non-ultramainstream distro.