Back in the early days of blogging, the medium was set apart by style as much as venue. It was shorter, punchier, almost never reported or edited. Blogs read very differently from magazines, and even more differently from newspapers. For some blogs, that remains true. But the last year has seen the rise of reported campaign blogs (and other reported blogs, but I'm going to use the campaign example here). Marc Ambinder, Ben Smith, The Caucus, the Trail -- blogs written by serious political reporters, some of them in a style approximating newspaper articles, all of them dedicated to gathering and disseminating new information (not commentary) about the race. Blogs are, increasingly, just a platform. They're set apart by speed, comments, lack of space constraints, ability to embed video, hyperlinks, etc. They're not set apart by a particular type of content. The terms "blogging" or "bloggers" are of almost no analytical use, as they don't describe anything more specific than "writers" or "writing."
Blogs have indeed come a long way, and they are increasingly a medium rather than a particular form of content. The rise of reported blogs further blurs the line between the mediums. There really isn't any meaningful difference between what Ben Smith does and what more traditional political reporters do.
In any case, even blogs that are strictly limited to commentary (like mine) are often more informative and penetrating than what passes for serious reporting. Bloggers like Glenn Greenwald and digby have done an excellent job over the past few years of exposing the corruption and laziness of the MSM, and it's a good thing that the media giants are losing their monopoly on news and analysis.