Alienware has always been one of AMD's big partners for Ryzen processors; it was one of the first companies to offer the original, AMD's launch into high core-count desktop processors, with the gaming desktop. That's a huge system, though, and now that AMD's latest (third) generation of prosumer- and gamer-focused , Alienware's cramming it into its midsize Aurora chassis (18.9 x 8.8 x 17 in/482 x 223 x 432 mm).
The new desktops are available now (hitting Europe in the first half of 2020), starting at $1,199 for a configuration with a Ryzen 5 3500, Radeon RX 5700, 8GB RAM and a 1TB hard drive; the Ryzen 9 3950X model will start at $2,350, with a Radeon RX 5700, 8GB of RAM and 1TB hard drive.
8GB of RAM and a 1TB hard drive, rather than SSD, is disappointing for the price and for a gaming system, though. And since the AMD systems support PCI 4.0, a hard drive is a waste of bandwidth and possibly even a bottleneck. It's possible that because of the power requirements for the processor it needs a more expensive 850-watt power supply (the base for an Intel config is 460 watts), and because the Ryzen 9 needs liquid cooling, Alienware made some trade-offs. An upgrade to 16GB on the current Intel-based models adds another $100 to the price and jumping to a 1TB SSD adds $320, so I'd consider a real Ryzen 9 entry configuration closer to $3,000.