It's been about a month since Microsoft released a new 20H1 ISO for Windows Insiders, when it released build 18990, but there's a new one today for those interested in doing a clean install. The new ISO is for build 19013 which was released last week to Insiders in the Fast Ring. The build has also been serviced twice: the first time was last Friday and there were no changes, and another update was released yesterday to fix an issue with Remote Desktop.
There hasn't been a ton of new features added to Windows 10 in recent 20H1 builds, and with reports suggesting that the update will be complete in December, it seems like there won't be a lot more in the way of major changes. Build 19013 only added new kaomoji.
In addition to an ISO for Insiders, there's also a corresponding preview build of the SDK. There's no blog post for it just yet, so it's not really clear what's new.
You can download the latest Windows Insider ISO from the Windows Insider website. For developers, you can download the SDK preview build 19013 from here, along with the matching builds of the Assessment and Deployment Kit (ADK), Windows Driver Kit (WDK), and Hardware Lab Kit (HLK).