Big Green Discusses enterprise environmental positioning and communications, for the most part. Well worth a visit.
Earth2Tech Well maintained, nicely written techno/green blog. Lots of good content here.
Environmental Leader "Daily news for corporate decision makers." Updated daily, EL offers a common-sense, easily scanned compendium of business environmental events.
Green IT Sourcing from Forrester Research "How sourcing and vendor management executives shape environmental strategy" sounds a little abstract, but the content here is pertinent and, for the most part, practical. (But, seriously, no update since December 12?)
green@work Today News tracking compendium about "positive progression" (!) in areas of environmental impact and sustainability, an offshoot of green@work magazine.
Greenbiz.com Frequently updated, generally relevant news source for the environmental/business value convergence. Reports are often well-nuanced and go far beyond the simplemindedness that abounds in green discussions.
Joel Makower's blog Full of interesting resources. Makower is the founder of GreenBiz.com. Check out the list of "blogs I track" if you want to go further and have the time. Product plugs by commentators on this blog can be a nuisance.
Rivoluzione verde Excellent Italian blog about environmental technologies and initiatives around the world. Nicely produced with lots of resource listings.
Science Codex: Earth Frequent updates from scientific publishing on what scientists learn about our little world. The other Codex areas ("Heavens", "Body", "Culture", "Tech") are also worth reviewing.