He has skill and athleticism so it will on depend on if his Chin holds up. Seeing as how he hails from the Isle of Glass Jaw, that is a very big "if".
Did you see that left hook Hatton hit him with? It must have had the blunt force trauma of a sledge hammer. Kell shook it off like it was nothing more than a pimp slap.
Devon would be easy work. Devon is your generic jab-jab-str8 southpaw. Killa Kellz knows how to throw a counter hook over the southpaw jab. It's over for Amir once Kellz takes away his jab by jabbing with him.
http://www.youtube.com/watch?v=kYaEGVIUxrc#t=7m01s Killa Kellz pullcounters his opponent's 1-2 with a hook. http://www.youtube.com/watch?v=kYaEGVIUxrc#t=7m20s Kellz calls his opponent's bluff or sees through the feint as he throws a right to take advantage of the opening presented by the feint. Kellz is that nigg@
Hatton is Feather Fisted and it still wobbled Brook. I have little hope that he will have a Chin, but from time to time England can produce a Froch, so who knows?
He's already at world level. Becoming a world champion is the very least he'll do. When that'll happen, is hard to say. He's being brought on ridiculously slow.
He is on a par with Alexander, Bradley, Khan, Malignaggi and fighters of that level. If he continues to improve he will be better than them.