Mostly just adds support for the new Uno and Mega boards: Get it here. From the release notes:
* Added support for the Arduino Uno and Arduino Mega 2560.* Including ATmega8U2 firmware used by Uno and Mega 2560.* Including source code to optiboot bootloader used by the Uno.
* Including source code to the stk500v2 bootloader used by Mega 2560.
PS: the Eagle files for the two boards are now up, too.