I'm considering moving to an improved Atmel development board with a built-in real time clock, like the XMEGA-A3BU Xplained. See it here: http://www.atmel.com/tools/xmega-a3buxplained.aspx?tab=documents
A sales rep indicated it would share the commands with a Mega 2560.
Their Studio 6 IDE (C/C++) is amazing, compared to basic IDEs I'm using. Their starting prices are comparable to that of the Arduino Uno.
Has anyone converted any Arduino sketches or code to the Xmega platform?