Neville is pureblood, remember when Dumbledore was explaining about the prophecy and he said that Voldy chose Harry a halfblood over Neville a pureblood, so NEVILLE IS PUREBLOOD, he is not the prince, the Half-Blood Prince is Tom Riddle.
Think about it, he's not Voldermont (this was stated in book 2, he grows up to be Voldy, but he isn't yet), He's half-blood, and he's the heir of Slytherin (there's gotta b some royalty in dat)
wow, this is HUGE! i'm so pumped for book six now...not that i wasn't before...but now, more then ever! 😄 I actually read it on her sight last night...but was made fun of for thinking it possibly true 😛
but i don't think the half blood prince is Tom Riddle...cuz i know he "grows" into voldemort...but i think in essense, he really is voldy...i think thats to technical, the prince is gunna be somebody we're not expecting...