Yelawolf holds a bit more promise for me. His lyrical subject matter is pretty limited - being white, being white trash, being Southern white trash - but he has a fluid, gripping flow going for him. On his major label debut Radioactive, however, Eminem muddies his protege's talent somewhat by insisting on filling the back nine of the album with blatant stabs at crossover material.
Hardly any of it works, with the notable exception of "Let's Roll", a catchy as fuck duet with Kid Rock with a monster chorus that just won't quit. Kid Rock's contributions are limited to singing harmony on said chorus, and frankly if dude wants to move further and further away from actually rapping I can't imagine having a problem with that.