From what I've seen of Nocturne:
Lame laner, awesome jungler (like master yi)
good DPS considering he also has a fear (fear OP) and a spell shield
Q and R scale with AD so he has some awesome burst
Ulti scares the hell out of me
Squishy as hell, I looked at him as Poppy and bursted 75% of his HP without ulti OR DFG.