To start off:
AMD Navi in July! Card showcased is called Radeon RX 5700 series. It appears to trade blows with the RTX 2070. More details on Navi at E3 on June 10th at 3PM PST.
AMD Ryzen 7 3700X - $329 USD
AMD Ryzen 7 3800X - $399 USD
AMD Ryzen 9 3900X - $499 USD
Available July 7th (CPU confirmed, GPU likely)!
NVIDIA’s announcement to follow shortly.
Edit: Revising to prevent spread of misinformation.