It seems like documentaries have suddenly become an acceptable format for a popular film release. From political releases such as Death of a President and the upcoming Jimmy Carter: Man From Plains, to scientific subjects such as In the Shadow of the Moon and more grounded ones like March of the Penguins, they all beg the question: Why the sudden approval of a predominantly slow, plodding, and — gasp! — educational medium?
I say the person we have to thank is Al Gore. As the former next president of the United States, Mr. Gore has a kind of fame not usually found in Hollywood. Any other star would've made a film about global warming into a made-for-TV special, but Mr. Gore propelled An Inconvenient Truth into theaters. Both his 2000 election loss and global warming are topics that are, for better or worse, controversial; people wanted to see what this presidential candidate, politically quiet for six years, had been up to, what his new angle was. It wasn't like Morgan Freeman narrating March of the Penguins; as engaging as the film was, there's little debatable about birds, and they didn't represent Mr. Freeman's politics or platform. But global warming? It's either the biggest scientific hoax of all time, or one of the greatest threats to life on Earth. It was a killer combination of topic and delivery, and its accolades, awards, and accumulated profits have opened the door for other documentarians.
And so I'd like to thank Mr. Gore, not for either alerting us to this peril or perpetuating this worldwide fraud, but for showing that documentaries can be edgy, accessible, and enjoyable — and, in so doing, expanding the diversity of film genres, subjects, and debates. If you haven't already discovered this cinematic style courtesy the Discovery or History channels or the works of Ken Burns, check it out; you'll find it's grown up from the inescapably dull classroom lessons forced upon you a generation ago.

Hmm, I would credit the movement more towards Michael Moore — whether you agree with his ideas or not, he did prove to a lot of people that documentaries could be entertaining and thought-provoking. Not that they weren't already, it just took a big jab to society's arm for them to notice.
I am dying to see Ken Burn's new doc on WWII — looks incredible — with found COLOR footage!
Ken Burns' The War on PBS was indeed excellent. While relying less on actors reading diary entries than The Civil War, the footage and veterans' recollections were still powerful and provided the perspective of common soldiers in that global conflict.
I also agree that Michael Moore's polemics, as well as Burns' classy documentaries, have helped revive the respectability and immediacy of that genre.
I agree that Michael Moore and his works played a pivotal role in the emergence of this genre. Bowling for Columbine was perhaps below most people's radar, but Fahrenheit 9/11 definitely was not. But I've never heard anyone call for Al Gore to be treated for treason like they have Michael Moore; and certainly 9/11 earned the ltter neither Academy Awards nor Nobel Prizes.
In the tradition of An Inconvenient Truth comes a film from Robert Redford, Willie Nelson, and Despair.com: The Unforeseen.