It definitely won't have as much "content", in a general sense. Just the lack of hundreds of equipment to customize your character guarantees that, but when it comes to length, this type of level progression needs a more lenghty experience to feel satisfying, imo.
Returning to a DS1 style of world design like Miyazaki has been hinting (not sure if the previews say it wasn't true, though, didn't watch them) wouldn't mean anything for a game that only has 3 areas, for example.
If it was a linear action game, I would even say I'd prefer if it was shorter, even 6~8 hours short, but for this type of exploration I need more.