We recently upgraded all of our client websites to WordPress 3.3. Most of the WordPress core upgrades deal with security and bug fixes, and our clients do not need to be concerned with the details. However, the 3.3 release introduced some new features that will change some of the ways you use WordPress.
Drag-and-Drop Media Uploader. When you use the Media > Add New menu or the Add Media button in the post/page editor, you will see a prominent box with a dotted line border. You can drag and drop files onto the box to upload them, which can be much faster than navigating through your folder structure.
Upload/Insert Buttons Consolidation. Previously, there were separate Upload/Insert buttons for adding images, audio, video, and media. In WordPress 3.3, these have been consolidated into a single button labeled Add Media. You can use this button for any type of media upload.
Flyout Menus. When you hover over menus in the WordPress backend, the sub-menus will appear to the right automatically. This makes the administration menu more compact, and lets you access menus with fewer clicks.
Performance Improvements. It’s unlikely that you will notice a difference, but some technical changes to the core code has improved WordPress loading time.