The curriculum is changing, once again without public discussion

The writing curriculum for K-12 students is changing in Massachusetts and elsewhere, but it isn't at all clear that these changes will move more students towards a meaningful high school diploma.
What kind of writing should kids do at different educational levels? We know that writing is related to reading, but what does that mean for the K-12 curriculum? What are effective ways to develop a range of writing skills? What are the elements of a sound K-12 writing curriculum?