SWTOR Troopers are divided into two major advanced classes: the Vanguard and the Commando. As demonstrated in the video, the Commando is there to deal high amounts of damage or call on medical droids to revive allies. The Vanguard displays his prowess as a fortified wall between the his comrades and Sith opponents.
The full video is available after the break, so take note of the differences not only in the armor but in the abilities of the two advanced classes. It will be very interesting to see whether the fabled all-Trooper guild can be pulled off effectively.