Wound Points: Equal to Constitution score (includes Con damage.)
Vitality Points: Equal to normal hit points gained for class levels, including max at 1st level and Con bonuys at every level.
Critical Hits: Applied directly to Wound points. All critical multipliers are reduced by 1 (so an axe gives an x2 critical. This includes for a coup de grace.
Fatigue: Any time you take wound point damage, you become fatigued (-2 to various stuff and no running/charging as normal).
Unconsciousness: You become unconscious at 0 wound points, lose one every round unless you stabilize; you die at -10 wound points. If you take wound point damage, you must make a Fortitude save (DC 10 + wound point damage taken) or fall unconscious. (Slight chance the base DC might be 15; I don't have it in front of me).
Natural Healing: You heal one vitality point per level per hour (just like subdual damage in 3E. You heal one wound point per day, just like ability damage.
Toughness: This feat gives wound points, not vitality points. I figure it would also extend to the higher-level toughness feats in MotW.
Falling: Reflex save DC 15 + 1 per additional 10' fallen. Success means the damage applies to vitality. Failure means damage applies to wounds. Tumble still reduces effective fall by 10'.
NPC Classes: do not get vitality points, only wound points. This is why stormtroopers fall like wheat before a scythe.
Real wounds: if the DM feels something is an actual injury rather than something that can be avoided by luck, it applies to wounds instead of vitality.
Out of vitality: once you hit zero vitality, any remaining damage is applied to wounds, and all rules for taking wound damage apply. If you hit exactly zero vitality points, you are staggered for one round.
Armor: armor provides damage reduction, not a defense bonus, though this damage reduction applies only to wound damage. Masterwork armor increases the DR of the armor, and does not reduce the armor check penalty. MW armor can go as high as +3
Weapons: MW weapons give a damage bonus, not an attack bonus. They also can go to +3.