The latest version of Scaleform GFx 3.2 supports most Flash 8 AS2 functionality. The Unreal docs will outline all the details soon.
Later this year (Q4 2010), Scaleform GFx 4.0 will be officially released with initial Flash 10 AS3 support. It will have its limitations in terms of the latest Flash 10 and AS3 features, but each new release will continue to be more complete, similar to the way GFx v1.0 - v3.2 continued to support more Flash 8 AS2.
Scaleform will have alpha and beta versions of GFx 4.0 (AS3) available earlier, but it's Epic's decision on when and which version to integrate into UE3 and UDK. We normally recommend only using beta or final versions for shipping product.
Scaleform provides a separate integration compatible with UE3 source SDK (not UDK, because it's binary only), which is updated monthly to be compatible to the latest Scaleform GFx beta and final releases. The Scaleform integration supports additional components that are optional and not required for console game developers, but that some may be interested in. Again, it will be outlined in the Unreal docs soon.
So for now, everyone can use the latest Flash CS3, CS4, or CS5 tools to publish to Flash 8 AS2 format to create stunning front end menus, high performance HUDs, even animated Flash textures on 3D surfaces.
Scaleform has also added 3Di (3D interface) rendering, which allows you to tilt and rotate any element in 3D using a simple set of ActionScript extensions. The current 3Di rendering via ActionScript is the same as Flash 10's native 3D, which will be supported in GFx 4.0.
There's even a new Scaleform AMP performance tool that can be used to profile Flash content running inside your Unreal game. Please keep in mind the tool is new and limited in functionality (and may have an issue or two), but we're working hard to make it as useful and powerful as possible. We're eager to hear your feedback on how to make it even better.
You can visit www.scaleform.com for more information and videos.
UE3 Source licensees and evaluators should register at www.scaleform.com/register to receive additional Flash/Scaleform support. We have many C++ and Flash experts on staff to help.
UDK developers will be supported through the UDN community.
We look forward to working with everyone!