Not only would it be great in a classroom, but also I think my own four year old son would enjoy some of these short readings as bed time stories. He really likes checking out non-fiction books from the library, and learning about the world. (Also, I always read to him in Spanish). Conexiones would be a great addition to parents who home school, or are working to help their children learn Spanish.
This book could honestly be the backbone of the cultural and geographical curriculum of a Spanish class. There are so many cross curricular connections, it would be very easy to work with other departments to plan a joint lesson or unit. This includes: history, science, math, geography, biology, food, art, legends, celebrations and more. The cultural dictionary itself is such a rich resource and depending on your objective there are many possible avenues to expand. Knowing your class and their interests, you can figure out which direction you would want to go with all of the possible content.