Adobe released the first beta of the new Text Layout Framework (TLF) for Flash Player 10 and AIR 1.5. Built on the new text engine of Flash Player 10, the framework offers advanced typographic and text layout features. It supports bidirectional and vertical text, multi-column layout, text flow around inline images, advanced antialiasing and transformations (alpha, rotation, etc.) for device fonts and much more.
Flex Gumbo, the next release of Flex, already includes the framework and offers text components that use it. Flex 3.2 and ActionScript developers can download the framework and use it to develop their own text components and classes. For Flash CS4 Professional users, Adobe offers an extension to integrate the framework in their projects.




I had to deal with bugs, but most of them were resolved by the SDK team a few days after I submitted a bug report (that was really great, thanks to the Flax team).
The other problem was changes in the API, which can happen anytime (Gumbo is still alpha) and which breaks compilation of your code. But following the svn commits, you generally know exactly what changed and what you have to change in your code.
Regarding Arabic support, it works great. The text components make it really easy to use the TLF. The only difficulty for now, is that Gumbo does not yet support mirroring for the visual components (to make RTL interfaces), but with some hacking you can get it to work, especially that now you can easily develop your own layout components.