This
It also completely screws over dragonborn.
Also, the bloodied condition doesn't have to refer to characters that are battered and bruised, it could just refer to a character that got wounded once. HP are all the character's resources for staving off wounds, and this should also let them stave off injury. You can still have realism and danger without this rule. DnD already uses the 'unconscious' condition to describe characters that are badly battered and bruised.
If you do implement this rule, certain character builds are going to become obsolete, some powers and magic items will be useless, and you will probably have upset players dieing very quickly unless you send weaker/fewer monsters. Moreover, attacks that add statuses will become useless. Why deal 1[W] and daze a target for one turn when you can choose a power of the same level that deals 3[W] and bloody the monster, weakening it for probably the rest of the encounter.
I don't want to discourage creativity. You see the condition bloodied and you begin to think about how it would affect the character, which is encouraged, but I want to point out two important ideas.
Game-play and fun take precedence over realism: weakening bloodied characters will probably make them enjoy the game less.
Bloodied does not mean mangled: to me, bloodied means hit. Until you become bloodied, the damage you take is just means that your morale is down, you are getting tired from dodging so much, the arcane or divine power that protects you from attacks is being used up... When you become bloodied you're enemies land a solid hit on you. An adrenaline surge keeps you from dropping and you keep fighting, but one more hit like that and you could go down.
If you implement this, it could work if your players are open minded and experienced players, but I wouldn't suggest it otherwise.