Thanks to a demonstration by Eiji Aonuma, after months – years – of Nintendo keeping a lid on the game's mechanics, we now know a bit more about the game's mechanics.
The first is Rewind, a remake (or evolution?) of the Stasis ability in the previous game that freezes objects in time but instead reverses their trajectory or actions. This was shown in conjunction with a fallen piece of rubble that then went back high into the air, giving Link a route to one of the game's many Sky Islands.
The majority of the video is spent explaining the Fuse mechanic, which appears to be strewn upon by opponents from time to time.
The Ultra Hand, which bears the same name as Fuse, has the ability to move simple objects around as well as the ability to construct elaborate structures from different trailers.
Finally, there is Ascend, a somewhat less well-known but extremely useful ability, wherein Link can leap to any ceiling above him and swim through it to get out of the top, and it can be applied to large boulder caves as well.
These are likely to be all four new abilities that we'll be seeing in the game. They're both quite impressive and appear to have a wide applicability, so we'll have to wait to see how they stack up.