I agree. I've been following him for a long time (before he quit his day job!), and he is absolutely a great writer. Daringfireball, along with HN, are truly my only daily reads.
However, while I think he's generally spot on with his Apple analysis, I can see how his detractors are turned off by the smidgeon of smugness in some of his articles.
Don't forget that Apple has officially taken a liking to him, and that he is getting unusual access for a "regular guy". Pre-release hardware to review, invitations to private Apple media events, etc.
It would be in his best interest to not anger Apple or they instantly cut off his access. See: Walt Mossberg.
This is what all of the industry do. If you review graphics cards and you put out a negative review, no more pre-release graphics cards for you.
But Gruber's significant articles (like this one) are based on information that is public available. Most people just sees a chair, they don't see the thinking behind the chair.
What Gruber does best is to explain how Apple thinks, I know of no journalists that comes anywhere close to understanding Apple.
I agree that he probably understands the motivations and spirit of Apple better than most. My point is that he's now a part of the system in a subtle way, and to think about it when reading his coverage. He's no longer just a guy with a blog.
Andy Ihnatko is less of a fanboy, and still quite insightful about Apple. He has a very good natural sense of which rumors are probably true. And he's much funnier.