The Great Grammar Debate

Dave White at Do Some Damage has rekindled a longstanding debate (I'm sure I responded to this years ago at his old blog...). The question is how important grammar is in the process of learning how to write. He correctly notes that meaning is paramount, but I think he incorrectly wants to make a division between meaning and the grammar and word choice and spelling issues that plague student writing. Anyway, here's his post. Read the comments for our back and forth.