Nocturne isn't in that bad of a spot right now he is still decent just not broken like he was in season 1 or even season 2. Season 3 wasn't that great for him, but at the same time it wasn't that great for a lot of junglers that relied on ults in their ganks. Season 4 will be great for junglers that can offset farming and ganking which is what Nocturne does best.
If he ever does receive a rework it won't be because his kit is bad it will most likely be because of the frustrating mechanics in his kit (his ult for the most part). Nocturnes ult will be severely changed, but the rest of his kit will be slightly buffed to compensate. Even then this will not happen for a really really really long time if ever since over a dozen champions are in dire need of a rework than he is. Reworks are not always done because a champion is bad or even too good. You gotta take in mind how these champions interact with players and what counterplay is involved.
Morello has pretty much posted the list of champions that are getting reworked in season 4 and every single one of them need it because of the frustrating anit-fun mechanics in their kits.
Shaco
Alistar
Poppy
Sion
Warwick
Zilean
Urgot
Source:
http://forums.na.leagueoflegends.com/bo ... 4#43478654Oh and lets not forget the champions that are currently in the rework phase right now.
Skarner
Xerath
Jayce
Rengar
Yorick
Possibly even Nidalee.
So don't expect too many new champion releases in season 4.