In a somewhat regular Friday occurrence, Microsoft has released a Cumulative Update to the just released build 22581 for both the Dev and Beta channels, upping the build number to 11581.100. As usual, this update does not add any new features or fixes, and is designed to test the servicing pipeline.
In case you missed it, the Windows Insider program this week consolidated the Dev and Beta channels for a short time, allowing Insiders to make a switch from Dev to Beta. Once the tracks diverge again in the coming weeks or months, Dev Channel Insiders won't be able to revert back to the Beta Channel without doing a clean install of the operating system.
Anyway, have fun downloading this new build!