i wud like to add that we are all under the speculation or most of us ne way, that the half bllod prince is someone already in the books. and another titbit i wud add is that jk has stated that the mirror sirius gave harry in OoTP ( we are all sad he died i know

..) wud not have helped the way we thought it wud help, but it will help him alot more than we think, and we will find out more in books 6 and 7,let me know wot u think.............................................. also i have a feeling that perhaps aunt petunia maybe a a witch but as she detests the wizarding world decided to not go to hogwarts, my reason for this is jk woz asked if petunia woz a squib and all she sed woz no but.........., let me know wot u think of this too