John is the Senior Product Manager for Photoshop at Adobe. I love his unvarnished enthusiasm for things related to Photoshop and life in general. He can play on my team anytime he wants.
Tom Hogarty and the rest of the Lightroom crew post here, but not as often as John Nack posts on his blog.
DPR is the first place I go to find reviews of equipment I'm considering. there are also several RSS feeds that are valuable.
PB is a great site with news and reviews.
This is a special page on PB that's devoted to a list of resources for Lightroom.
This site is managed by Jeff Schewe, an independent (very!) photographer based in Chicago. He's not a shill for Adobe because he calls things as he sees them.
This site is managed by Martin Evening and Jeff Schewe. The latest news about Lightroom is often posted here first. Also, Martin often posts "preview" chapters of his books here.
This is a great site with lots of news, reviews and how-to's.