The Raspberry Pi 4 has been released, despite us not expecting a 2019 release.
This upgraded Raspberry Pi replaces the BCM2837 SoC with a newer SoC, the BCM2711, which replaces the four ARM Cortex A53 cores of the BCM2837 with four Cortex A72 cores, clocked at 1.5GHz.
There are 2GB and 4GB RAM options, and, you guessed it, the 4GB RAM model is more expensive. But the Pi 4 should definitely be a good PC replacement, which is why it deserves a good PC OS too.
I'm looking at Ubuntu here because the Ubuntu MATE image for the Raspberry Pi provides almost the same experience as the desktop image does. Hopefully, when Ubuntu add Pi 4 support to the linux-raspi2 kernel and release an update to linux-firmware-raspi2 updating the bootloader files, the Ubuntu MATE team could look at adding Pi 4 support to their Raspberry Pi image now or in the next release while continuing to use the Ubuntu-provided kernel.