I think that what is relevant here is something that was said in the opening post, i.e.
"What kind of information you can trust completely and do not check?"
The problem with most sources is that they are secondary sources and at best they can only be experienced opinion.
Google is deliberately vague in its announcements, so that sources are left to speculate on what they may or may not mean, so "news" is usually a copy of what they have said (which is what I meant by being secondary sources) followed by an analysis.
Even when there seems to be general agreement over something, it doesn't mean it is correct.
I find it interesting sometimes to look at forum threads and articles from some years back, and to compare what the analyses were of what was going to happen with what has actually transpired. Just to give one example of something I was looking at yesterday, 5 years ago there were strong rumours that PR would be removed from the Google toolbar, and 3 years ago (from a Google spokesman) that it could be renamed.
So I don't believe there is any information from any source that can be trusted completely and not checked. As I mentioned in an earlier posting, if I find something I investigate it. If I want further opinion I will find a forum thread or start one. Even then, it is really up to individuals to form their own opinion, because there is very little SEO news that can be easily established as being factual.