From the blog post announcing it:
We’ve decided to make the handbook available to everyone for a number of reasons. Among them:
Transparency: At a time when trust is an endangered commodity in the financial and media worlds, it’s important that news consumers see the guidelines our journalists follow.
Service: As we’ve seen over the past decade, the barriers to publishing have dropped so that anyone with an idea and a computer can be a publisher. But it’s also become clear that publishers have a varying standard of truth, fairness and style. Our handbook is a good place for budding journalists to begin.
Geography: Reuters serves a global audience and the handbook recognises the cultural and political differences that our journalists face in reporting for the world. This is a handbook not just for English-language journalists in the United Kingdom or the United States, but for wherever English is used.
I hope that this action cause plenty of follow-ups by other news organisations, including the one i work for; dpa