Plenty has been written on the imminent demise of newspapers. Rather than reiterate the basic points, I'll just point you at the two best articles I've read on the topic (props to this blog for originally pointing me to these). If you've got others, post them in the comments, I'd love to read them.
The New Republic has an article explaining the dangers of world without newspapers, specifically arguing that deep investigative journalism is crucial for preventing corruption, but isn't being replaced.
Clay Shriky writes the best general overview of the issue I've read. In particular, he contextualizes with the last big communications shift, the invention of the printing press.
I don't believe its all of for-pay content that's at risk. The latter article in particular is of a quality that could survive behind a pay wall. It's a well-researched, well-written deep examination of a complex issue. Were I to summarize or rewrite the content, something would be lost. It's not just the facts we're looking for in a high quality article, but the way they can provoke our thoughts.
Unfortunately, that's not the norm in newspaper content. Rather, most articles are read for the facts of a current event. We want to know the results on a healthcare reform vote, what outrageous thing Kanye did, who won the game last night. When publishing was expensive, you could derive value from facts. But unfortunately, most facts ultimately hold little value in a rich communication medium.
Once a news source states some fact they've uncovered, the readers can pass the facts along. In the hundreds of thousands of blog filling the internet people are taking in news and spitting it back out, with their own commentary. The abusive case of just reprinting AP articles and putting ads around it is easy enough to deal with. But copyright only applies to the text you write, not the facts in it. One of your readers can rewrite your stories, and then the world will flock to the free source over yours.
The alternative of giving newspapers ownership over the news stories they break is a scary one. Imagine if fox news uncovers a scandal around Obama. Even if we gave them only a day's worth of ownership over presenting the facts of the case, that means that for a full 24 hours the only voice informing the world of what's happening, the only voice setting the tone of the debate going forward, is Fox News. For society to function, everybody needs to be able to discuss what's happening in the world. For that to happen, you can't wall off facts. And if that's true, there's little incentive to pay for facts when you can get them for free immediately afterwards. Of course, that returns us to the core issue of who will discover these facts for us then. It's a tricky issue, but I don't think for-pay news sources are going to remain the solution for long, unless they can start adding something over and above the straight facts.