I was thinkin that if Nas (or any MC) had the opportunity to do Unplugged or a similar format, AND they had the opportunity to enlist the services of The Roots, they would be CRAZY not to do it. Jay-Z just beat 'em to the punch.
But Nas (and I ain't a Nas-hater) has zero stage presence, so a Nas Unplugged ain't likely to happen (unless he been at home in the mirror practicing).