If papers such as the independent, etc. had been given this information, im sure there professionalism would have been the same or higher. Outside of handed-on-a-platter reporting, the Guardian has massively cocked up in the past (leading to the arrest of sources, etc.).
[1] https://en.wikipedia.org/wiki/News_of_the_World_phone_hackin... The whole story goes far beyond what is mentioned in that article: huge corruption in the Met, an axe murder in a london car park and of course a government communications director, his prior involvement in the hacking and his affair with a certain newspaper executive
To look at those papers you wouldn't suspect something of this magnitude is even going on.
Journalists are particularly cynical people constantly chasing after anything that will get their by-lines in front of faces.. i dont think we're looking at a paper which has suddenly found its 21st C. political morals, but rather a paper that has suddenly found whistle-blowers queuing up at their door.
What's really disconcerting is that the other outlets have decided this isn't sufficiently "in the public interest" as to disobey the notice.