There's a new function with transformation masks in MM3D where if you do any kind of jump (jumping off something, backflip, sidehop, etc)
when you press a mask button he will put on the mask instantly after he lands on ground (
http://youtu.be/USuibSveq-A)
When you do this and press R to shield (while targeting) before hitting the ground Link will "store(?)" the transformation until you let go of R and even you can talk to NPCs and he will transform after talking to them.
Now like in OoT3D, when you have an item in hand and you press R while targeting you put away the item (they fixed it now where some items like the deku stick, he will shield with the stick) so you can't do some glitches like timestop for example or the glitchy weird Z targeting with bow on use. So then after some playing around again I found out you can combine both of these and make this:
https://www.youtube.com/watch?v=GRtLhWoEcWYSo you can get the glitchy bow camera, bottle in hand, (another items in hand i believe)
There are several other things i tried out like zora ledge grabbing, which they fixed you cannot longer grab a ledge after transforming into zora while in water
http://youtu.be/oPBTGOhBwykIce that blocks the path to Mountain Village doesn't freeze you anymore, they act like a normal boulder when you slash them and I also passed the gate that goes to Great Bay, but the demo doesn't have the area so I crashed lol (works with zora only though :\
http://youtu.be/26JSMmME-MY)
And as for all things listed by Ben before there are videos but not gonna post them unless people wanna see them.