Yesterday WordPress released version 3.9 that has some nice new features. When working as web agency one of the best features is a quite small update but a real timesaver when working with non technical customers that it that they can now paste directly from Word to the content area. There were numerous customer when I worked at my previous job that complained that a page broke in IE and all was from the extra code Word adds when copying.
The update includes the latest TinyMCE which is more responsive and improves the experience, I actually prefer the mobile web than the WordPress app.
When working with more critical clients with a lot of visitors the widget preview is great because before you hade to change widget live and check if it was right but no anymore.
Here is a good blog post with more about the updates and below is the official video: