Apple made sure not to keep the hardware side of things going w/ the iMac Pro. It was already talked about earlier this year and they made it official w/ specs, pricing, and availability for the most part. Apple is already hailing it as their most powerful Mac ever - even beating the Mac Pro by their standards.
So what makes this Mac so powerful? It ships w/ an 8-core Xeon CPU that goes up to an 18-core Xeon CPU, a 5K display, AMD Radeon Vega GPU, 16GB of VRAM, up to 4TB of SSD storage, and 128GB of ECC memory. All of this will support 4 Thunderbolt 3 ports that can connect up to 2 high-performance RAIDs, 2 5K displays, and supports 10Gb Ethernet for up to 10 times faster networking. You'll also get up to 11 teraflops to better support real-time 3D rendering & high-frame rate VR.
The iMac Pro is already set to arrive in December starting at $5,000. So who's gonna start saving for Apple's most powerful PC - for now.