With an increased play rate to boot. And while it is still early in the patch and the love affair will die down, I actually expect his winrate to stabilize around 50-51%.
This was actually one of the best, most well balanced buffs I've ever seen from Riot. Nasus, I suspect, is exactly where he needs to be right now while still being healthy for the game.
I haven't read too much into PBE for preseason 7 changes but I suspect Nasus will be stronger based on what I do know and the fact we will probably go through an assassin meta, a meta Nasus excels in the best.