Static defenses have never been the strong suit of the Terran. While the Protoss had the versatile if not fragile Photon Cannon and the Zerg had the stronger but more specialized Sunken and Spore colonies, the only Terran static defense that didn’t require the expenditure of valuable population units to create was the Missile Turret, a low-defense surface-to-air bombardment which had a slow rate-of-fire and was all but ineffective against certain airborne threats like Mutalisk swarms.

When defending against ground units, the Terran Bunker was likewise fragile, and was really only a means to station infantry units in one spot and protect them for longer periods of time. While the effectiveness of these defenses could be aided by SCV support, they still were a drain on the population to be used effectively. Many Terran commanders would also place lines of Siege Tanks, which would even further strain their population capacity.

This problem may be mitigated, although evidence suggests that bunkers and Siege Tanks are still a core part of Terran base defense. The TF-620 Nomad, a new construction unit will be replacing the Science Vessel, and is said to also have the ability to construct automated defenses.

Details on the versatility of the Nomad defensive structures remain unclear, but it is known to have the ability to construct small Auto-Turrets, and is implied to have other construction capabilities as well. It would not be much of a stretch to say that if they still exist, Missile Turrets can likely also be built by the Nomad.

From the game-play videos, the Turrets appear serviceable, but not overly powerful in either offense or defense. Whether or not there will be stronger methods of static defense remain to be seen, but at least the option is there.

One thing Blizzard has shown is the population limit has been vastly increased since the first iteration. Depending on the scope of this change, it may be that the Terran unit-based defenses are perfectly serviceable. On the other hand, money maps on Battle.net are extremely popular, and if the game lasts long enough, population becomes the most important resource on the battlefield. Whether or not the Nomad will mitigate this problem for Terran players remains to be seen.