Pre-release Update 1 was released on October 10, 2004. Version numbers are:

Kickstart 51.15
Workbench 51.1
U-Boot 1.1.1 (04-Oct-2004)

This release is available as a free update and bundled with new AmigaOnes. It adds support for the MicroA1 (ľA1). The official list of things included in the update is:

Shown in the Workbench 1 screenshot are some of the following features: