You raise some interesting questions:
- In having the horocrux removed from him, will Harry become familiar enough with their "signature" to tell that the diary is one?
- Will the new familiar be "just" another owl or something that reflects both his love of flying and his parseltongue capabilities? An occamy (winged snake, I believe), perhaps? Or a dragonette?
- What level of double-take will Draco do on meeting the "new and improved" Harry and how bad will he get spanked this year?
- Will the "new and improved" Harry have a greater feeling for others and take Ginny and Luna "under his wing"?
- And -chuckle-, of course, just how big a fit will Ron pitch, esp. when he finds out that Harry -did- write him and he never wrote back?
I can see lots of fun times ahead for all.