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Not exactly "Armageddon", but the triggering of nuclear weapons close enough to the asteroid to divert its course, but far enough away to prevent impact was found by NASA to be the best option we have for asteroid prevention.
Specs
Pros
Pro Technically viable
Unlike other options that require the precise application of small forces, nuclear explosions would require minimal detailed information about the asteroid while still being effective.
This results in a simpler mission design that would only need basic details about the physical characteristics of the asteroid and its trajectory. The mission could also be designed to incrementally deflect the asteroid over multiple blasts which would reduce the overall technical risk of the mission.
NASA has already designed the mission and spacecraft required to deflect an asteroid via nuclear explosions.
Pro Highly effective
In a 2007 report to congress NASA found that the use of nuclear standoff explosions were 10-100 times more effective then any other alternative considered in the study.
The primary benefit of this approach is the amount of force it exerts on the asteroid. Unlike other techniques that require years to work, this approach would be effective on asteroids mere months away from impact.
This is critically important as our goal for 2020 is to be able to detect 90% of the near earth asteroids. Our current capacities are well below this, and even when implemented the new systems will result in a significant portion of the asteroids remaining undetected. This number increases dramatically if 20-30 years notice is required for the deflection of the asteroid, making the ability to quickly react to an incoming asteroid critical to our survival.