I think he can still be easily shut down during laning phase.
On the other hand, I've only played post-buff nasus like 4 times so far and only once my solotop vs yorick was somewhat disturbing [probably because we had shit jungler], but not that bad, but then we lost that round because shit-jungler and another feeder dragged the game down into a lake of crap.
So yeah, if team isn't shit, Nasus sounds really good now.
[but I heard riot plans to nerf infinite stacking on veigar and nasus :| ]