Having watched the trailer a couple of times, what I'm seeing is a more symmetrical, polished helmet sculpt; the abdominal armour plates are either broken into more sections or have more strapping; the torso armour definitely has more strapping; the under-suit/body-glove appears to be padded in spots like the elbows; and the back of the belt is vinyl or plastic like a TFA trooper rather than canvas as in the OT.
Additionally, the troopers with pauldrons and backpacks (what we recognize as 'sandtroopers') appear to have the standard knee-plate as opposed to the original, rougher-edged diamond-shaped plates; I'm guessing they will have ridged connecting bridges at the shoulders too, rather than featureless -- and the armour looks to have slightly different, beefier proportions overall, likely to allow for movement, comfort, and larger actors than they used in the '70s and early '80s.