Do you mean nigger or negro?
I think negro is just a bit archaic, and to say it now would be somewhat insulting, though not the end of the world.
Of course if you ever called anyone a nigger it would definitely be the end of the world. It's a racially charged word and that's just how it is. I wouldn't say it around anyone, much less someone black, however, as part of a quote, or when singing along to a rap, I wouldn't think twice. It's not me saying it.
But nigga... that's a whole 'nother topic. There is a good book by the name of "Nigger" that discusses a lot of this, including the way in which the black community has sort of co-opted the word.
Anyway it wouldn't shock me if I heard it, but I live in Texas and there are still more than a few racists around. Since I am white it's not completely unheard of for me to overhear white racist assholes saying it to each other, however I've never seen a non-black person say it TO a black person. That WOULD be shocking.
So yeah. But as a quote I think it's stupid to get offended by that... it's a quote. In fact most times I've run across that situation, my black teacher encourages the squeamish white student to just go ahead and say it.
Also, in the interest of equity, you'd think "cracker" would offend me as much as "nigger" offends a black person, however this isn't the case.
Or is it? I dunno.
Race relations are utterly fascinating.