The Message Behind the Door

First the message, a refresher for anyone who doesn’t have it imprinted in their mind or engraved heavily into their computer desk:
He looked rather like an old lion. There were streaks of grey in his mane of tawny hair and his bushy eyebrows; he had keen yellowish eyes behind a pair of wire-rimmed spectacles and a certain rangy, loping grace even though he walked with a slight limp. First off, I’d never heard the word "rangy," so more for myself than anything else, I looked it up in the dictionary. Rangy, apparently, is another word for gangly or lanky; so we’re probably looking at someone quite tall.
The description puzzles me and I’ve found myself yelling at my computer as the comments come flooding in: it’s the HBP!; it’s Godric Gryffindor!; it’s McGonagall’s husband!; it’s McClaggan!
Now, before I spontaneously combust, I want to try and disprove some of these theories:
“It’s the HBP.” – I think that’s almost an insult to Jo! I have no doubt in my mind that she would NOT make it that easy for us. Although the whole book isn’t going to be centred around the Half Blood Prince we’ve all been talking over, she didn’t give any information away about who the Prisoner of Azkaban was before book 3, what the Goblet of Fire was before book 4 and definitely not what the Order of the Phoenix was before book 5. I don’t think it’s going to be any different this time around, my fellow Potter fans. I don’t think we’re going to find that out until the book is right in front of our goggling little eyes.
"It’s Godric Gryffindor." - To put it simply: he’s dead. I don’t think it’s ever been specifically stated, but the dude lived over a thousand years ago and just like R. Ravenclaw, S. Slytherin and H. Hufflepuff, he’s dead, buried and gone. If they weren’t, there’d be no reason for the Sorting Hat and no wizard is immortal unless they have the Philosophers/Sorcerer’s stone, which has been destroyed.
"It's McGonagall’s husband." - It’s never been stated that Minerva is married, and I’m not seeing that as an option until Jo reveals McGonagall's marital status.
Lastly, "it’s good old McClaggan." – He/she has only been mentioned once and already they’re about as famous as the Mona Lisa. To defy this theory, I call upon a quote from Rowling’s talk at the Edinburgh Book Festival:
"I found the name McClaggan the other day, which I think is a great name. There is a McClaggan in book six because I thought that it is a surname that is too good to waste." I don’t think this McClaggan person is going to have a main role – I think he/she is going to have a minute part, a little like Archie in Goblet, the guy who made Hermione giggle by refusing to replace his muggle nightdress with trousers...gotta love the guy!
By the sounds of things, Jo just put him/her in because she liked the name, which is as good a reason as any. Any main parts that Jo thinks up already have names, I believe, even if they do end up being changed (like Rita being called Bridget) and are planned beforehand. Jo’s now halfway through the book, and she states that she only came across the name the other day. Sounds like a bit part to me.
I have to say, I don’t think we’ve come across the character described before and I’m one of many speculating that maybe, just MAYBE, this guy’s the new defense against the dark arts teacher (in which case I feel sorry for the Hogwarts first years because he doesn’t come across as the friendliest-looking person in the world). Either that, or it’s just a random passage about a random, bit-part person.
Frankly, I don’t think we’ll know who this dude is until the book’s published. We may not like secrecy but Jo does, and we respect that. I don’t think the "Brain Behind Harry" is going to give away too much until the book’s out there to be devoured.