Uh...It`s not a "new" genre. People have been trying to do it for a while now. I guess you`ve never heard any of koRn`s CD`s, have you? They usually have one of those cross over tracks on a CD, but, I don`t feel like looking into which, right now.
As for the Jay Z/Linkin Park "Encore/Numb" thing, well...The Jay Z contribution is aweful. His lyrics aren`t at all good. However, the beat to the song, and the fact that they pulled off this fusion is respectable all in it`s own. I`m thinking of buying the CD that has this on it, so I may see if they did anything else that impresses me, seeing as how the last song of theirs I felt was worthy of praise was "My December."
But, anyway, yeah...it`s not "new."