Wonderful & different!
I loved this. The surprising changes from fanon - not to mention canon- were disconcerting and a delight. It's nice to have my fannish mind knocked sideways now and then into a new configuration - a very pleasing one!
I love your mix of hot sexual attraction, romance, and the realism of people painfully recognizing that their planned pairings simply aren't going to work (*cough*I suppose that goes for JKR's Epilogue too, heh). What's going to happen to Ron? Will stubbornly proud Lucius's willful death cause complications for Draco and Hermione? And will Severus ever fess up about who took the picture? Will he and Harry ever be open about their hopes and fears? And ... what happens when Harry graduates?
All awesome. You really opened up a lot of possibilities... that is, plot bunnies! I hope you might feel like following up on this story some time. As it is, though, it's a gem. I'll definitely be reading it again whenever I want me some "feel-good" Snarry happiness. *\o/*