Features removed in Windows 10 Fall Creators Update

Windows 10 version 1709 "Fall Creators Update" is the upcoming feature update for the stable branch of Windows 10. Also known by its code name Redstone 3, it is expected to be released in a couple of months, probably in September 2017. Microsoft has published a long list of features which are removed or considered deprecated in the upcoming release.
The official announcement comes with the following list.

Features removed in Windows 10 Fall Creators Update

3D Builder app

No longer installed by default. Consider using Print 3D and Paint 3D in its place. However, 3D Builder is still available for download from the Windows Store.

Apndatabase.xml

See this link

Enhanced Mitigation Experience Toolkit (EMET)

Use will be blocked. Consider using the Exploit Protection feature of Windows Defender Exploit Guard as a replacement.

Outlook Express

The non-functional legacy code is removed.

Reader and Reading List apps

Functionality to be integrated into Microsoft Edge. See Edge gets EPUB support in Windows 10 Creators Update and How To Annotate EPUB Books in Microsoft Edge.

Screen saver functionality in Themes

To be disabled in Themes (classified as "Removed" in this table). Screen saver functionality in Group Policies, Control Panel, and Sysprep is now deprecated but continues to be functional. Lockscreen features and policies are preferred.

Syskey.exe

Removing this nonsecure security feature. They recommend that users use BitLocker instead. Syskey.exe utility is no longer supported in Windows 10 RS3 and Windows Server 2016 RS3

TCP Offload Engine

Removing this legacy code. This functionality was previously transitioned to the Stack TCP Engine. For more information, see the following PFE Platform Blog article.

Tile Data Layer

To be replaced by the Tile Store.

Trusted Platform Module (TPM) Owner Password Management

This legacy code to be removed.

Features deprecated in Windows 10 Fall Creators Update

IIS 6 Management Compatibility

Microsoft recommends that users use alternative scripting tools and a newer management console.

IIS Digest Authentication

Microsoft recommends that users use alternative authentication methods.

RSA/AES Encryption for IIS

Microsoft recommends that users use CNG encryption provider.

Microsoft Paint

You can always restore the classic Paint app using the following tutorial: Get Classic Paint back in Windows 10 Creators Update

Sync Your Settings

Back-end changes: The current sync process is being deprecated. In a future release, the same cloud storage system for syncing settings will be used for both Enterprise State Roaming users and all other users. (Currently, these users use different cloud storage systems.)

System Image Backup (SIB) Solution

Microsoft recommends that users use full-disk backup solutions from other vendors.

TLS RC4 Ciphers

To be disabled by default.

Trusted Platform Module (TPM): TPM.msc and TPM Remote Management

To be replaced by a new user interface in a future release.

Trusted Platform Module (TPM) Remote Management

This legacy code to be removed in a future release.

Windows Hello for Business deployment that uses System Center Configuration Manager

Windows Server 2016 Active Directory Federation Services – Registration Authority (ADFS RA) deployment is simpler and provides a better user experience and a more deterministic certificate enrollment experience.

Windows PowerShell 2.0

Applications and components should be migrated to PowerShell 5.0+.

As of this writing, the latest build of Fall Creators Update released to the Fast Ring of the Windows Insider program is Windows 10 build 16241.