The details can be
found here.
There seem to be 3 main modes:
Game -- Play through the game normally. Hint system is available but not forced. So hardcore gamers could just play the game regularly and enjoy the challenge while more casual gamers can get hints if they get really stuck
Digest -- The game goes through important scenes (both movie and gameplay) in order. Essentially the game plays itself in this mode if you will. But you have the option of stopping the digest at any time and playing from that exact point. Plus when you choose to take control you are given the appropriate equipment and stats for that part of the game. No saving though, but it seems to be unneeded
Scenes -- essentially playthrough any puzzle or scene again. Like digest you are given the appropriate equipment and such.
What Nintendo is planning on doing is pretty insane and far more ambitious than some of you realize yet. This just might be the "gateway game" that gamers, casuals and non-gamers could all enjoy.
The main idea is Shigeru Miyamoto wants harder nintendo games without alienating casuals, non-gamers, the unintelligent, etc by having built in walkthroughs for the gamers that having touble with the game.