Looks like Windows 10 SDK gets renamed.
This post focuses on the Win32 wide of changes. Changes in the WinRT side can be found at https://dev.windows.com/en-us/whats-new-windows-10-dev-preview.
DirectX12 (of course)
The Spartan webbrowser (not sure, some Spartan-specific commands like IDM_SHAREPICTURE exists but no word on how to host a Spartan webbrowser)
new API partition WINAPI_FAMILY_ONECORE_APP
Windows Core Audio improvements: Prioritize buffer selection in Windows Core Audio APIs to reduce audio latency (e.g. alerts, game effects, game chats, user speech, movie etc) . Low power consumption audio is there for WinRT but not for Win32 :(. Well DJs are gonna be happy about this change.
Unsurprisingly some low power API for video codec too. Guess playing movies do kill battery life.
Losts of changes in the Certificate Enrollment API…. and what’s up with the desktop family guard macros? someone gonna try include the headers in a Windows Store app?
APIs for not domain/AD joined clusters. Wow the documentation is up in MSDN already. The Windows Server team is faster this time. Guess the consumer team fall behind because of the Phone edition.
Wow Microsoft is adding stuff to COM again. Did not expect this to happen. The REGCLS enumeration gets a new member.. after 15 years.
You are joking right? Why this empty ifdef in the tree control styles and extended styles? Looks like something got cut.
#if (NTDDI_VERSION >= NTDDI_WINTHRESHOLD)
API for Jet – Extensible Storage Engine version version 10, like the new 8-byte unsigned long long column type.
IShellUIHelper7 adds some more methods to the window.external object… like SelectUAString and getter/setter methods for experimental flag. Can I change between Trident and EdgeHtml this way?
Secured D3D in Media Foundation. Guess WebGL forced that.
Now you can customize the context menu in a PDF document displayed in a hosted webbrowser control.
Some new SQLite-specific surface in winerr.h. It sounds like everyone is using SQLite now?
New system folders like camera roll and saved pictures. FOLDERID_SkyDrive is getting renamed (of course) but will remain for some time for backward compatible reasons.
TODO: neerajsi-2013/12/08 – this should be moved to official documentation.huh?
Graphics streaming in Remote Desktop APIs.
D3D 8 (it is still there in Windows 8?)