Okay, I typed out a really long reply to your review because I was excited/stimulated by what you said and I got really into it, but then I realized that you probably weren't looking for a novel-lenght in reply.  So the short, normal-person response is:

Thank you for taking the time to review my fanfiction! I'm flattered that you think my piece is well-written. Thank you for your concern about the name change (this is the part that got me all excited).  I'll try really, really hard not to let Harry disappear completely, and hopefully if you bear with me you'll revise your opinion that I've turned Harry into a complete O.C. I hope that you'll keep reading and responding, and especially hope that you'll continue to let me know how you feel about whether or not you can still find Harry under the cloak. :P

Thanks, 

Cait!

...and if you ARE interested in my crazy-excited ramblings, here's what I originally wrote (Spoiler Alert for later chapters)...

First of all, let me apologize for taking so long to respond to this: I was, as I said in the piece, on vacation.  Like you, I often shy away from stories where Dudley has magic, but for some reason this time my muse took over.

Thank you for saying what you did about the name change. It's not my intention to have Harry disappear completely, although I can certainly see that it would appear that way from how I've set the story up so far. I can only implore you to bear with me a little longer. The name change is actually an important part of the plot.  I don't know if you've ever read the Shadow Children series by Margaret Peterson Haddix, but in that series a bunch of children are forced to take on fake identities. In one of the books, a character says something along the lines of, "They might call me Lee Grant, but in my head I'll always be Luke Gardner, and I'm sure none of the rest of you have forgotten your real names, either" (okay, that's a REALLY bad reproduction of the quote, but I haven't read that book since I was, like, ten).  ANYWAY, my point is that the name concept has intrigued me for a while. I mean, one of the best lines in The Crucible is when the main character says, "I've given you my soul. Leave me my name!" (That quotation is much more accurate :P) and the title of one of my chapters is based on the Shakespeare quote which says, "a rose by any other name would still smell as sweet." So, anyway, I wanted to get into the name question with this fiction.  My thought process was that:

1.) At first, Harry and Dudley would both be excited to change their names because a lot of ten year olds are excited about anything different (I quite distinctly remember wanting to be renamed "Sarah" when I was in elementary school). 

2.) Snape is particularly keen to change Harry's name because Harry was named after his paternal grandfather, and his middle name was James. However, he doesn't want to admit that to himself, so he's telling himself that both boys NEED to be renamed.

3.) Later, Harry and Dudley will have different opinions on the name change because, for all that he didn't connect with his father, a part of Harry will want the connection to his parents that he had when he was named Harry James Potter, whereas Dudley will be happy to change his name because he's trying to distance himself from his crazy parents. 

 And...yeah.  Stuff will happen.