Gaia 2.2.5 has arrived and has some great new features. Among these features, binding expressions, landing pages, and framework optimizing top the list.

Gaia now supports binding expressions in the site.xml, similar to how Flex does it with MXML. This makes things like localization much easier. You can assign a binding expression to a FlashVar, to a public property in your Main class file, or a public property in any page class file. Anytime Gaia accesses the binding expression, it uses the current value, so you can change it at runtime. This allows you to do things like change the language on the fly. Rule!

Also, a new page attribute "landing" has been introduced. This has been requested quite a few times and now it's in. This allows you to set any page as a landing page regardless of whether it has children or not.

Framework optimizing is a fairly advanced feature which allows you to reduce the size of your main.swf file by up to 10k by not compiling unused Asset classes. Why compile classes you're not going to use? With a single button press, Gaia automatically comments out any unused code based on which assets are present in your site.xml. Add some new assets, optimize again, and Gaia will uncomment any new asset types that are present.

There are a few other little items, such as being able to use an id other than index for the index page, optimization of the SiteModel class, and some AS3 bug fixes.

You can read the full release notes and download Gaia here:
http://www.gaiaflashframework.com/forum/index.php/topic,581.msg2436.html