I recently got write access to the AVR-Ada repository and now I have pushed my changes there.
These changes improve support for Atmega2560, Attiny13a, and Attiny2313 processors. Attiny13a and Attiny2313 are pretty uninteresting, although common, AVR processors. I happen to use them in my projects because they are cheap and that is why I also wanted better support for them.
On the other hand, Atmega2560 processor is used in the new Arduino Mega 2560 board. This means that next release of AVR-Ada will support the new Mega board out of the box. Some bits, like support for timers 3..5 and extra UARTS, are missing, but at the moment Atmega2560 should have about same features as Atmega328p supported.