Click on some of the links here, then read the articles. Seems to be about 50/50.
As for the last part of what you wrote: Ever consider that the decline in human attention span and the commoditization of news media might account for what you wryly observe as "get[ting] all the information you need from the headline"? And you would suggest that this is a good thing?
They are related, but different. I get all the information from a headline when the story has very little news to offer. Visiting Google News, some examples from the first page, and my reactions in parens:
- Fewer Americans think Obama has advanced race relations, poll shows (fluff)
- ATTACK ON FLIGHT 253 Accountability sought at terror hearings (more finger-pointing rather that addressing the real issue)
- Photos Purport to Show Woods at Rehab Center (celebrity fluff)
- Football legend Archie Griffin raising awareness of H1N1 vaccinations (celebrity fluff)
- More Men Marrying Wealthier Women (good for them)
- Palin and McCain will campaign again (and I don't give a pair of fetid dingo's kidneys until 2012. wtf are we doing reporting on presidential elections this year?)
- Jets-Colts Preview (sports, and not even "what happened" but a bunch of speculative fluff)
- Americans See Economic Recovery a Long Way Off (Captain Obvious is alive and well on staff at Gallup)
Essentially, I get all the information from the headline when the article is shit, and I read further when the headline suggests a possibility of worthwhile content. I was actually surprised and somewhat more hopeful at how many articles I clicked on while compiling the list above because they seemed possibly interesting.
Then there are inaccurate and misleading headlines. I don't know who is responsible, but a link on Google News for "Michelle Obama Unveils Anti-Obesity Initiative" links to a story called "Michelle Obama's Anti-Obesity Plan," and the article itself says she "is expected to unveil an anti-obesity initiative next month." Another article, entitled "First lady surprises White House visitors," is simply linked to a video of her shaking hands with people on the White House tour. WTF is this doing on the first page of Google News?