https://arstechnica.com/gadgets/2023/09/raspberry-pi-5-available-for-preorder-is-faster-and-has-a-custom-i-o-chip/

Nearly everything on the Raspberry Pi 5 has improved over the 4 model, particularly the way you can buy it. In a first for the single-board company, the 5 is available for preorder today from approved resellers before it's generally available by the end of October.

Perhaps most importantly, the 5 is being prioritized for individual buyers rather than commercial partners.