Nuclear Phynance is usually trotted out as the finance equivalent, but it's a forum. http://www.nuclearphynance.com/

Hacker News is really the best business-of-software site. http://inbound.org/ is essentially Hacker News for SEO/internet marketing.

For market news, it depends on what you want, but http://caps.fool.com/ is good coverage and socially-driven. Unlike HN, it has built-in features to show if a user's predictions about the future tend to be correct (only really possible in the stock world.)

The best general research and analysis sites are, in my opinion, still the curated/paid ones with on-staff researchers. I greatly miss my Roubini Global Economics subscription. I think, though, that someone could really cut down businesses like those with the right kind of site.