I was really not impressed with his velocity when I saw him on Pitch F/X. I don't think you're really going to see a lot of K's, or a lack of BB's from him.
As is, I think he's pretty near his ceiling already.
Not a wasted pick... but I don't see anything more than 4-5/AAAA type out of him.
This is kind of what I was afraid of. Still... any lefty with decent velocity is going to get an extended look.
Also: Norris putting up stats like this suggests that he's too good for the pitchers at this level (yes, it's SSS, but it's not like him walking and hitting homers is a new development). Time to move him up and see what happens.