Update 12 Dec 2012: The latest version of WordPress, 3.5 has been released.
There’s hundreds of improvements in this version which is scheduled for release on December 5.
You can test the latest version by downloading it or installing the beta testing plugin which updates the core every night. Whats called “bleeding nightlies’.
Bleeding Edge Nightlies
Once you’ve installed the beta testing plugin, you’ll need to select bleeding edge nightlies and and head on over and upgrade now.
Improvements & Changes
There’s several hundred changes which have been made to 3.5 and the latest version also includes the latest default theme, Twenty Twelve.
Here’s the official post by Andrew Nacin
This is a beta version which is not recommended for use on a live site unless you are a developer. This version may conflict with plugins and themes which are not compatible with the latest version.
Plugin and theme developers will be working making there software compatible by 5 December.
You’ll notice adding new images to your posts and pages is different. A range of images you have already uploaded to your media library will be displayed for faster and easier insertion.
Read more about WordPress 3.5 image and gallery features.
One of the things you’ll notice once you do update to the latest version is the removal of the Link Manager.
If you want to continue using this feature, you’ll need to install the Link Manager plugin. What WordPress have done is hide (disabled) this feature from the dashboard and created a plugin with the code which will be taken out of the core files down the track.
So your links will not display if you are using this feature until you install the plugin as they are in the database and not lost forever.
More to come soon.