Version 2.1 of the ArcGIS API for Flex is now available. To begin using it, download the new Flex API Library and recompile your applications.
The 2.1 version is fully backward compatible with your 2.0. We've added a few things and fixed a few things. The key aspects of the 2.1 release are:
Support for drawing circles and ellipses with DrawTool (sample).
Support for rotating and scaling features with EditTool (sample).
Support for OGC Web Map Service (WMS) - new WMSLayer class.
Improved support for touch events to make it easier to use on Android phones and other touch-enabled devices which supports Flash Player 10 or above. The Flex API now supports drag to pan, double tap to zoom in, pinch open to zoom in, pinch close to zoom out, and two-finger tap to zoom out. The latter three requires Flash Player 10.1 or above.
For a complete list of enhancements and bug fixes, view the What's New in 2.1 Flex API document.