I agree that there is a coincidence about Mark Evans. And I think that he will probably end up at Hogwarts as many of you have suggested. My question is...what is his relationship to Harry? Obviously not his brother because both parents were dead before his birth. He can't be from Petunia because otherwise his name would be Mark Dursley. The only logical explanation is that Petunia & Lily had a brother. That is the only way that they could pass down the name Evans, and I realize they say nothing of Mark's parents in the books, but who are they? and what do they do? I guess we'll have to wait and see, but I'm sure that somehow Mark will get his revenge on Dudley for tormenting him. Perhaps he befriends Harry because he looks up to him and he is the only other young wizard in the neighborhood. Maybe he even gives up his location to Voldy...I might even go as far as saying that this "brother" of Lily and Petunia might have been a follower of Voldy and that might be the slight relationship between Lily and Voldy. (not relationship like James and Lily had.) Maybe Voldy wanted Lily but he couldn't win her over, just like Snape. Of course, these are extremely far fetched scenarios...