A BLOG-ONLY NEWS DIET? Interesting report, but I don't see blogs in general -- and certainly not InstaPundit -- as a primary news source. InstaPundit is an opinion blog (see, er, the name and the motto), not a news service. I do try to call attention to stories that I think deserve more attention than they're getting from Big Media outlets, but that very effort means that InstaPundit isn't going to be "balanced."
Of course, reading about the stories that the Poynter report linked above treats as undercovered in the blogosphere also tells you something about the seriousness of Big Media in that regard. Paul McCartney and Harry Potter? Love 'em both, but there's not much actual news in those stories. . . .
UPDATE: Related thoughts here. And, perhaps, here.