Threat of Thassarian

Threat of Thassarian is a passive specialization ability for Frost death knights, available at level 74.

This is a key passive that makes dual wielding viable for death knights. Normally only the main hand weapon is taken in to account for abilities that deal damage based on weapon damage, such as Frost Strike and Obliterate, severely reducing their damage when dual wielding instead of using a 2-hander. This passive 'fixes' that problem for frost death knights.

Trivia
This talent refers to Thassarian, the first death knight to rejoin the Alliance.