Just announced: 8GB Raspberry Pi 4, 64-bit Raspberry Pi OS

Raspberry Pi Blog announced 8GB Raspberry Pi 4 on sale now at $75, and also introduced the early beta 64-bit Raspberry Pi OS.

source:
~ Raspberry Pi Blog - 8GB Raspberry Pi 4 on sale now at $75
~ You can find a link to the new 64-bit image, and some important caveats, in this forum post.

You can also read all about it in The MagPi magazine issue 94. Include download link for free PDF version.
~ https://magpi.raspberrypi.org/issues/94