Literary genres are important to me as a teacher because they help students to understand and guide their reading choices. I know some folks might think of genres as labels and therefore limiting and contrived. But they're useful guides for reading!
My 7th grade classes are in the middle of a genre mini-unit. I use my new books (yay!) to give examples and then assess their knowledge of different genres. Tomorrow I'm giving an open notes test in "science lab" style, i.e. each desk has one book labeled with a number. Students rotate around the room in number order and must identify the genre of the book at that desk and explain what information led them to their conclusion. Today they practiced this "lab" as review.
Here's a "flash card" style review game on Quizlet.com of literary genres (created by some teacher I know, ahem).
I also teach writing by genre. Teaching reading and writing by genre just is very natural and fun!