Yeah, it's a stupid idea. The End.
No, really. Here's why. Mark Twain wasn't a skinhead. Contrary to what Dr. Alan Gribben might have thought, Twain's usage of the "N" word in Huckleberry Finn had very little to do with the modern usage of the word itself. We live in an era where kids start to forget that African American people used to be slaves to the white folk, why, oh why, would you remind them for 200 pages in a mandatory reading. Twain didn't refer them as slaves he just called them...
Huckleberry Finn is not only a great novel, it's also a piece of American history. There was a racial problem back then and there's still one today. It's not as bad (nobody OWNS African-Americans anymore) and it surely take another form, but it's still going on. It's important that the "N" word remains, because it's important to remember we used to consider African-Americans as sub-human. We did it, it's a part of history and it's TO NEVER BE REPEATED. Twain understood that and chronicled it through his fiction, in the struggle of Jim. He uses the "N" word as an EXAMPLE.
Also, the term of "slave" is a pretty stupid replacement. It's a direct admission that African-Americans were slaves. Yes, it's OK to remember it, but fiction vehicles ideas through masses, so pound the word "slave" two hundred times in a mandatory reading in high school and white kids are going to call black kids "slave" two hundred times before the end of the day. It's going to confuse a new generation about the racial conflict in the U.S. Things happened for a reason and it's important to remember.
That said, that's what happens when you let an Academic Egghead take a decision with such social reach. These people are disconnected from everything, but their mind.