There are a number of updates that need to be made for 4.1 to both the handbooks and the Codex.
Handbooks:
There are several posts on Make/Core about changes in 4.1 that affect the developer handbooks:
Themes: New Template Tags in 4.1
Queries Improvements:
Shared Terms: An Update on Shared Term Splitting
Customizer API Improvements: JS/Underscore-template-rendered Custom Customizer Controls in WordPress 4.1
I still need to add a list of Codex pages here that will need to be updated with the content from these posts.
Codex Updates:
The following are the pages that need updated or created in the Codex.
If you would like to help, please leave a comment indicating which page you would like to work on.
New default theme:
- Twenty Fifteen page. We can use some of this content. Note: The custom color screenshots are slightly different from the .org version. Takashi Irie provided some screenshots that reflect the default colors available: https://cloudup.com/cNHOeJVOq-k (@kpdesign)
New features:
- New Distraction-Free Writing and inline image editing toolbar in Post editor – https://codex.wordpress.org/Posts_Add_New_Screen and https://codex.wordpress.org/Pages_Add_New_Screen
- New sessions logout button on Profile page – https://codex.wordpress.org/Users_Your_Profile_Screen
- New Recommendations tab on Plugin Install page – https://codex.wordpress.org/Plugins_Add_New_Screen
- New translation installation setting on General Settings and Network Settings pages – https://codex.wordpress.org/Settings_General_Screen and https://codex.wordpress.org/Network_Admin_Settings_Screen
- Appearance menu – Header and Background menu items now link directly to the Customizer.