AVaRICE version 2.12 has just been released.
Major milestone is the adoption of ICE firmware versions 7.x (JTAGICEmkII and AVR Dragon), which allows debugging of Xmega devices.
Many thanks to Detlev Kraft for providing the necessary information for this.
New devices added: ATxmega256A3, ATxmega16D4, ATtiny4313