Shitload of new stuff on the terrans.

[Emperor Pan I]

Anti-ground turrets don't exist.

However interesting to note, I'm pretty sure missile turrets have lost their detection ability, but they do indeed only hit air. Looking like the sensor and radar dome will be needed to do such.
Humans only new thing for "defense" is a Thor, and if you have seen the gameplay trailers it quite obviously doesn't get much of a job done in terms of defense.

 

[Renzokuken]

Thor is useless as defense.

 

[Wing Zero]

wow thor its counted as a building?

 

[Emperor Pan I]

Thor is built by SCVs, moves slow as shit, fires slow, and takes several seconds just to turn around. Units like stalkers could easily blink behind, fire off like 4 shots, then blink back to the other side before thor can turn to attack. Cobra's are fast enough to mostly circle and fire on thor, killing it and barely getting attacked by it.

Great for Artillery tho. Needs good AA, siege tanks etc. support.