As for RC3, on the other hand, not only is it a major bug fix release (thanks to everyone who started making reports last week), but also includes two new features (and others that were hidden before).
Editor Wiki Code Buttons
This has been a desired feature for a while now. RC3 adds two more segments to your editor toolbar. The first is a set of buttons for linking to articles in each (important) namespace. Buttons are included for each of Special, Template, Book, and Help, as well as an additional button for your content namespace. Additional buttons for additional namespaces must be created and configured on your own.The second set of buttons are for non-linking codes and will change depending on whether you are editing an article or a standard post.
Namespaces on Forum Display
Because Namespaces are required to be top-level forums, they cannot be placed in categories, and especially when using Forum Links to set Main Pages, they tend to be an ugly addition to Forum Home. Now, even if your Namespace's Display Order is set to 0, you can use two new forum settings to configure if and how they will display in the forum list.The first allows you to set a "Display Parent" so you can add them to a Forum Category or another Forum without corrupting your cached articles. The second allows you to set a "Display Name" for the forum or Namespace so that you don't necessarily have to use what shows in the URL.