Miles Davis knew what hip-hop is at its core - it is an outgrowth of jazz. Even if it's gone in weird directions, that is what it is at its center. Great rappers like Mos Def (now Yasiin Bey) have played on this - the sound of trumpets and horns actually flows in hip-hop as if they're designed to:
I think alot of rappers and hip-hop artists know this on a deep level. Hip-hop as it was at its epoch is over - and maybe that is for the best. Rapping will never go away and will be a part of a more well rounded world of R&B. Nas seemed to get this with his album Life Is Good - Miles' horn would have been a worthy ingredient to his song "You Wouldn't Understand:"