https://www.raspberrypi.org/products/raspberry-pi-4-model-b/

https://www.raspberrypi.org/blog/raspberry-pi-4-on-sale-now-from-35/

OpenGL 3.0 hardware acceleration for desktop ui / web browser

H.265/H.264 hardware accelerated decode for 4k60fps video

Drive two 4k HDMI monitors

1, 2, & 4 GB SDRAM options w/ 4GB at $55 price point

1.5GHz quad-core 64-bit ARM Cortex-A72 CPU

 

I'm pretty hyped with the big changes to USB and Ethernet:

Quote

The Ethernet controller on the main SoC is connected to an external Broadcom PHY over a dedicated RGMII link, providing full throughput. USB is provided via an external VLI controller, connected over a single PCI Express Gen 2 lane, and providing a total of 4Gbps of bandwidth, shared between the four ports.

The frustrating IO bottleneck where networking and USB shared a chip (and bandwidth) is finally gone.  The RPi 4 has a solid future capable little server.