RIA on the desktop
Drag and Drop support : the LiveDocs is here
Multi-window applications : the LiveDocs is here
Local file system access : the LiveDocs is here
Local SQLite database storage : the LiveDocs is here
Complete html rendering : the LiveDocs is here
Full AIR code hinting and error reporting, AIR Debugging and profiling, AIR Application packaging and signing : the LiveDocs is here
Data Visualization
Advanced Datagrid : the LiveDocs is here
OLAP DataGrid : the LiveDocs is here
Datagrid : the LiveDocs is here
Charting components : the LiveDocs is here
Testing
Performance profiler, Memory profiler : the LiveDocs is here
Support for automated functional testing : the LiveDocs is here
Interactive debugging : the LiveDocs is here
Design View
I don't use "Design View" of FlexBuilder much, sorry :)
(Some source-code made by Design View is horrible, I think.)
Designer/developer workflow : Flex Skin Design Extensions & Flex Component Kit for Flash CS3
( You need your Adobe ID. )Coding tools : Code Editing in Flex Builder
Performance
SWF size reduction : I think so, but Flex 3 Components is a little bigger than Flex 2. But we have FlexFramework cache feature now. The LiveDocs is here
Web-tier compilers for IIS and Apache : Adobe Flex 3 Compiler API User Guide
Working with Data
Web Service Introspection : the LiveDocs is here
Code-gen wizards for CF, Java, PHP, .NET : the LiveDocs is here
Browser integration
Deep linking : the LiveDocs is here
JavaScript and Ajax wrappers, Flex/Ajax bridge : the LiveDocs is here
Localization
Dynamically load localization resource bundles at runtime : the LiveDocs is here
