Edit: Updated! One of the styles has been confirmed as Hlaalu!
The armor styles of Morrowind are iconic for the whole TES franchise, so I think it would warrant its own thread to discuss what we know so far.
The Morag Tong style will likely (finally) show up.
However, Naryu's armor shown in the trailer and in the screenshot below is not "Morag Tong" style.
It's most likely a costume, as you can tell by the seamless integration of armor parts.
The following screeenshot is a headscratcher.
It appears to be light Morag Tong armor in cut and style (see concept art above).
However, it bears the emblem of house Redoran.
This would suggest that there are armor styles associated with the Great Houses.
Taking a closer look at other screenshots, the rounded pauldrons of the Gah-Julan bonemold style.
The style has since been confirmed as Hlaalu style.
The following screenshot shows the Hlaalu style very prominently.
Both screenshots also feature classic bonemold style helmets.
The one in the next screenshots also has spikes on top, suggesting heavy/medium variants again.
Alongside is a shield of an uncertain house. The shape would fit either Redoran or Hlaalu.
The armor with the tabard has been seen in several screenshots, but cannot be identified as belonging to a certain house or armor weight.
Next, we can spot the Telvanni Emblem on the shield of the character on the right.
The same armor is visible in the next screenshot on the character on the right.
Notice the rounded elements on the shin guards compared to those on the character to the left, who most likely wears a variant of the Hlaalu style seen in previous screenshots.
The armor is visible once more in this screenshot, this time with a helmet.
The style is difficult to associate with a house. It could be Telvanni by association with the shield in a previous screenshot.
However, the helmet by itself most closely resembles the Redoran Watchman's helm from TES3.
Overall, there are at least three discernable styles. One that resembles classic bonemold and has been confirmed as Hlaalu, the one seen in the last screenshot, and the known Morag Tong style.
Some house emblems appear on some of these armors, but it is difficult to establish a clear link between the styles and the houses.
If you have anything to add or object to, please reply!