It's probably common knowledge that all is not well in the Arduino household.
A rift has opened up between the original founders, who started Arduino.cc and their long term hardware builder, who has now registered Arduino.org
These two organisations will continue along divergent paths, whilst their lawyers fight it out.
Arduino.org - as a hardware supplier, were responsible for introducing a lot of the new hardware designs, such as the Due and the Yun - which are a move away from the earlier Atmel AVR boards.
In general, hardware suppliers need to keep ahead of the competition, because in the end, everything design gets copied and the market gets flooded with cheap imports from the Far East. So it's understandable that Arduino.org, want to put themselves in a position where they can innovate, and take on new product designs from other design houses.
Meanwhile, some of you will have noticed that Arduino.cc are spewing out new versions of the Arduino IDE, almost on a weekly basis. We quickly went from 1.60 to 1.63, and if you are a Due user or are making use of the GCC ARM compiler tools, you will found that you are somewhat left out in the cold.
Fortunately Arduino.org, have dragged themselves out of this quagmire of incompatibility , and released their own version 1.70. This continues to support all the newer board and processor variants, and currently looks like the best way forward. At least until the dust settles in the Italian law courts.