We're releasing an update package on WU for PC build 10240 today. It will install automatically or you can check for updates to grab it.
It will be described as a security update, but that's just because it's cumulative and includes the last package's security fix.
It is a package of fixes based on reported issues in 10240.
The update is now live and you can grab it from Windows Update in the Settings app.
The company had recently announced that, moving forward, it would adopt a Windows as a Service model, with updates continually being pushed out to the final product; this is our first example. The company is still looking to test its delivery systems to ensure a smooth upgrade experience for all the users of Windows 7 and 8.1 who will be availing themselves of the free upgrade on July 29.
Source: Gabriel Aul