No, 80 Levels, sorry. Man, 80 worlds would just be ridiculous (not that I'd complain)
There are 8 worlds in all (probably not counting secret worlds, if any). According to NP, the themes are Plains, Desert, Tropical Island, Forest, ice, Mountain, Sky, Bowser's Hideout. The level order seems very Mario 3 to me, though
NP also said that levels will have multiple exits (a la Mario World) and have Mario 64-esque missions.
Also, all the Mario 64 Minigames are included and some have been redone with multiplayer modes!
This is sounding like a kick-tush Mario game.
@ smfan - Apologies.