WordPress 4.0 a good round number might be released perhaps in August.

Something that really should be celebrated with some awesome new features.

For instance:
– Reopening and extending the Media Grid Library Core Plugin:
Media Library Core Plugin Post

– A core plugin worked on today is the Front End Editor – similar to this could also be added to the backend in the on hold CEUX Core Plugin project.

The Core Plugin feature has limited success from what I have seen from development for 3.8 and 3.9. As there are just too few developers taking part. http://make.wordpress.org/core/features-as-plugins/

4.0 is a big release and it would be great to see even more developers contribute to this version. (Actually the developers are treating this like any other release.)

Having surveys asking for what features people want to see in 4.0.
Having the results on wptavern or elsewhere for all to see and to comment on.

Starting to create a buzz around the big 4.0 mark. Having some big cannon features in place.

Possible features as I see it:
Front End editing seems to be one of them.
Another could be a good overhaul/redoing the Media Library.
Total overhaul of multisite to better incorporate it into WordPress (blurring the single and multisite networks).
Then a few more and a bunch of minor improvements.
Examples like: drag&drop of all posts/pages (move posts/pages similar to menus today creating subpages. Closing/opening a branch with subbranches etc). Duplicate post/page. Easily jump between any post or page with a drop down. Improving commenting. Improving featured content (core plugin was partly made for 3.8 but project was cancelled).

I also posted some of these thoughts at:
http://wordpress.org/support/topic/thoughts-on-wordpress-version-40

Do also check out my article on suggestions for making WordPress easier to use.