Right now, you can't disable automatic updates in Windows 10. You will get all updates eventually.
In some environments, this won't work. Some environments need to keep computers static. And it's undesirable to disable the Windows Update service because we may need, for example, college students in a "intro to computers" class to download updates as part of classwork.
Do we know if Microsoft has publicly stated whether RTM will have the ability to completely disable updates?
My understanding is that the Home version will still force automatic updates, but other versions (eg. the versions intended for the environments you mention) might have the option to stop it.
From here:Which I thinkmeans there won't be a choice for Home users.Feature Deprecation Section
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Windows 10 Home users will have updates from Windows Update automatically available.
My current understanding is that Windows Update for Business will allow domain-joined PCs to delay -- but not disable -- updates.
But I wasn't sure if Microsoft just set the preview version of Windows 10 to automatically update to help with diagnostics.
I am praying that RTM allows the Pro and Enterprise versions -- whether domain-joined or not -- to disable updates. We basically won't be able to use Windows 10 in computer labs (where DeepFreeze is installed).
There's always a way ... MS might not provide a nice interface to do something, but group policy or registry modifications have always allowed users to make Windows 'theirs'.
It's understandable why MS wants to keep all machines at the same release levels, but it's also understandable that many users have requirements that don't fit the "one size fits all" model.
No, according to the Microsoft Keynote where Windows Update for Business was announced, you would be able to choose from a variety of servicing profiles, from no updates, to only security patches (no new features), to the whole ball of wax, and be able to choose when and which machines go them.
However, the end users themselves are less in control and can only delay the updates. Eventually, they have to get applied (assuming WUFB profile says they should be).
It's unlikely though, that you will be able to pick and choose which updates you can install, it will be either all or nothing for each servicing profile, but I could be wrong about that.