Blogs are useful for the discovery of serendipitous information. There are plenty of news sites, and many blogs will repeat the same stories. The big value add is having someone else who will highlight just those things you are likely to care about; once you have found that you have similar tastes to Ethic, following his pointers is a big time-saver. Beyond that, once you have established similar tastes, you can try tangential items that you might not have tried or even heard of if not for this one dude you know on the internet with similar tastes. My Little Pony: Friendship Is Magic, really? (Hence Amazon’s “people who bought/looked at this also bought…”)
But the opposite is useful, too. Once you know that some movie reviewer is a doofus who you always disagree with, you can start using his reviews as a guide, just with the scores reversed. It is really hard to find your perfect opposite, but when you do, treasure him. I have someone on my RSS feed specifically because he reliably gets really excited about games that will crash within three months of release. I need to find his equivalent for the stock market.