For those unfamiliar, thu'um was mentioned in the Pocket Guide to the Empire, 1st Edition, in the section on Skyrim.
The Nords have long practiced a spiritual form of magic known as "The Way of the Voice", based largely on their veneration of the Wind as the personification of Kynareth. Nords consider themselves to be the children of the sky, and the breath and the voice of a Nord is his vital essence. Through the use of the Voice, the vital power of a Nord can be articulated into a thu'um, or shout. Shouts can be used to sharpen blades or to strike enemies at a distance. Masters of the Voice are known as Tongues, and their power is legendary. They can call to specific people over hundreds of miles, and can move by casting a shout, appearing where it lands. The most powerful Tongues cannot speak without causing destruction.
http://www.imperial-library.info/content/pocket-guide-empire-first-edition-skyrim
Now, look at Dovahkiin, the Dragonborn - he appears to have something coming out of his mouth, almost like a breath of fire. However, giving the setting, could it be that the Dovahkiin is using thu'um?
Thu'um and its effects would be an interesting addition to TES's magicka schools - calling to people could be similar in implementation as conjuration, moving with a shout like mark/recall, sharpening blades a buff to Armorer skill, shouting itself a 'force push' type destruction attack. Or, perhaps it could be an entirely new school of magic, with these effects as spells within it?
I can't find any lore on whether or not shouting is limited to Nords. Regardless, I hope we'll see it in some form:
Today, the most ancient and powerful of the Tongues live secluded on the highest peaks in contemplation, and have spoken once only in living memory, to announce the destiny of the young Tiber Septim (as recounted in Cyrodiil). In gratitude, the Emperor has recently endowed a new Imperial College of the Voice in Markarth6, dedicated to returning the Way of the Voice to the ancient and honorable art of war.
http://www.imperial-library.info/content/pocket-guide-empire-first-edition-skyrim
Could we visit this college for a basic introduction to thu'um, then seekout the masters for a greater understanding and ability?