The second major build since the "split" in channels in the Windows Insider program happened has arrived. Now standing on its own, and free for Microsoft to explore with, the Windows 11 Dev Channel is introducing a new search box option on the Windows desktop.
As a reminder, since the Dev channel tests concepts and ideas, this doesn't mean that this desktop search box will roll out to everyone in a future Windows release. Microsoft warns about that upfront and the fact that even after a reboot and installation of this build, not all Windows Insiders might see this feature. Anyway, this seems to be part of Microsoft's new model of "exposing lightweight interactive content on the Windows desktop," per today's changelog.
You can see that with how the search box surfaces and lives cleanly in the middle of the desktop. It looks very reminiscent of the Spotlight feature in MacOS, and a bit the floating search bar that was first teased in Windows 10 Redstone 4 back in 2017. For those who do not like this, it can be removed by right-clicking on the desktop and “Show more options,” and toggling the “Show search” option.

Overall, this search box seems like a quick way to open Edge and other online content, and we're sure that some people will like it -- but it seems as though more things like this could be on the way soon. In the changelog, Microsoft mentions this as "the first exploration in this area," when talking about interactive content on the Windows desktop. That's just speculation though. Here are other notes from the changelog.
There are three known issues in this release. For the first, some games that use Easy Anti-Cheat may crash or cause your PC to bug check. In the second, certain apps in full screen (e.g., video players) prevent live captions from being visible. Lastly, Certain apps positioned near the top of the screen and closed before live captions are run will re-launch behind the live captions window positioned at the top.
ISO files for this build are also available if you want to manually download and clean-install the release. Happy downloading, Windows Insiders!