i'm not too sure about this, but on mugglenet(i think) it said that the hb prince would be someone completely new.someone who we have never heard of before.the story wouldn't be so interesting if it was a character we know a bit about already.with hagrid i doubt there is a chance he could be hbp.he is a half-blood but is he a prince? where does it say that his mother was queen of the giants? that would mean grawp would be a prince too since he is hagrid's brother so hagrid must be rulerd out as a possibility-unfortunately.and dumbledore, well we know minimal about him.that would make it a good plot if he was hbp.but honestly, the reasons for havin Fawkes are unknown to all of us.his knowledge about the sword could only point to him as being a relation to the gryffindor heritage.if he is halfblood and his mother was the witch it would make perfect sense.godric was way into educating muggles with magical talent, so it wouldn't be strange if dumbledore's mother married a muggle to keep the line of wizards growing, even if they turned out halfbloods.godric didn't care about the blood of a wizard or witch so he wouldn't mind having halfblood relatives.but haryy is probably the true heir of gryffindor and that rules out that dumbledore being the hbp coz harry has no living relatives thru his dad and that would mean he and dumbledore were related.we'll just have to wait for the book to come out and find out for ourselves what is cutting.