Update 14 August 2014

For 4.0 planned release 27th of August – there are very few Core Plugins. Perhaps just one the Media Library Grid Plugin.
I hoped that additional Core Plugins would also be developed this time around but there is just too little movement going on.
Check the dates for the weekly chats.

Check out my Making WordPress easier to use article  which is updated regularly.
Below are thoughts for WordPress 3.9.

An update 23 January 2014.

What features should be included in Core Plugins for WordPress 3.9?

For WordPress 3.9 trac tickets (reported bugs, feature enhancements etc) are being worked on.
There are many feature enhanced tickets check the full list here:
Next Major Release – WordPress 3.9

Here is the trac list for 3.9 by priority.

For additional information check Make WordPress Core.

https://github.com/helenhousandi/wp-style-guide/

Here is my own list of improvements I would like to see in WordPress:

– Duplicate post or page.
– Draggable post/page listings.
– Category color.
– Changing Footer text.

– A new Media Library Grid system Core Plugin was somewhat created Check my Media Library Post .
Shawn Andrews also made a Tags system in it that was really never finished, so it got commented out.
Today we have a sort uploads folders into date, what about another option by category/tag?
A userdefined uploads folder sorting.

– Favicon
– Primary menu should auto select main menu location.

WordPress Categories

A lot can be done to improve how category pages are seen.
– Styling the category page with a title, image, links, background color or image etc.
– Styling what each post looks like within the specific category. Rounded box, border and color, background, shadow etc.
One column, two column, three column, featured post image left/below/right. Sorting of posts.

Additional options for the user profile page:
– The use of TinyMCE or similar to style the author bio.
– Profile image selection. To be used instead of a Gravatar.
– Author Widget.
http://wordpress.org/plugins/fancier-author-box/

There also needs to be a control as to how the author box will show. Top/bottom of a post. When?

WordPress Comments
– Options to turn on/off all comments for pages/posts. Or select which gets a discussion area or not.
– Might as well style the comments section as well.
– Additional comment features.

Easier way to enable multisite.
There is just too much work to get a multisite up and running. It should be in place by default.
Or by clicking in a box or some other option to enable multisite.

– Shared media across network. http://wordpress.org/plugins/network-shared-media/
– Shared posts across network.
– Shared login across sites.

http://wordpress.org/plugins/multisite-enhancements/

For additional features check my Making WordPress easier to use post.