[Dawn Bonnevie]

An interesting thing to note about the nonfiction trend, from my school district anyway, is that it is emphasized increasingly the higher you go in grade level. We are expected to require students to read a certain percentage of fiction / nonfiction based on grade level. In addition, science and social studies instruction takes a serious backseat to reading and math at the k-2 level. There just isn't time for hands-on or experimental science or social studies if we are to fit in the required reading and math time. Therefore, most of the concepts are taught through reading units.  What that means for me as a teacher is that if I am to read a nonfiction book to my students, or assign them a text to read themselves, I might prefer one from the perspective of a child / scientist DOING science and social studies (as opposed to straight informational) so that the students experience in some way what they are missing by not doing it themselves. 
My administrator asked us at a recent meeting how we felt about no science or social studies (as a separate curriculum) in 3rd grade. 

[Bobi Martin Posts: 224 Status: Offline Writers open the world to readers. WWW]

It's frustrating to me to see some subjects being removed because there isn't enough time for them. How are we supposed to produce more scientists, engineers, and so forth if all we're teaching is reading and math?  Don't get me wrong--we need math and reading. But eliminating subjects means teachers who realize the importance of the missing subjects then have to work them in through their reading assignments. This makes more work for the teachers and isn't as good for the kids as actually studying science and getting to do some kinds of simple experiments themselves. Grrrr.

[Dawn Bonnevie]

Bobi, it is extremely frustrating!  The premise is that children need to have rock-solid reading and math skills at a young age in order to do the demanding science as they get older.  I love science (was a bio major) but understand this line of thinking. Prek-3 is 'learn to read' and 4+ is 'read to learn'. Indeed, 4th grade begins the requirement to read textbooks. 
All the more important that nonfiction be engaging and not too dry or fact-heavy. IMO too much nonfiction is too busy and over the heads of young children. There are some great science series for young kids that are narrative, especially in the learn-to-read series, but I'd like to see more traditional, beautiful picture books that are the other way around...narrative with a science topic. 
I hope that CCSS brings back the total immersion in literature for the younger grades. I don't think the basal programs will go away (there's so much pressure for 'research based' instruction and the basal programs promise that) but hopefully, we'll be given time to actually do read-alouds outside of the basal again. Time that probably will only come from less science and social studies. 
Now, don't even get my started on time to do projects!