Since it seems to be making a comeback, it should probably be listed here as well.
Weapon specializations that add crit % (axe/dagger/fist) only effect the hand(s) for which you have a weapon of that type equipped. Even though the character sheet shows 5% additional crit when a(n) axe/dagger/fist is equipped in the MH, your OH will not receive that crit bonus with a weapon of another type equipped.
Source:
Rogue DPS Spreadsheet