D'karr
Adventurer
Well in 3e you don't want the PC to go into the negatives because that implies a serious wound.
In 4e there is a situation that it works just the same. When you go into negatives and have no healing surges left.
As I said upthread, getting stunned in 3e and going into the negatives in 4e are quite similar if not quite identical.
Except when the 4e character has no healing surges left.
However, one place where 4e DOES have it over 3e is in recovering the abstract side of hit points. I love the warlord in this regard. I love that they inspire their allies as this is something that no previous edition of D&D had ever really attempted and it made sense with how HPs have been defined since the start. Should it work on a seriously wounded character though? I think not. Sometimes a PC might be so done that all they can do is nod at the warlord before collapsing in a heap.
Collapsing in a heap is usually what happens when you have no healing surges left. If the DM decides to "narratively" describe HP loss as "wounds", which the "rules" don't force. Then nothing prevents him from "narratively" describing the SPENT healing surges as the same "wounds", when the character "narratively" jumps back in the action. Which the rules don't force or prevent.
Even more significant in this matter is the fact that if you go into negative Hit Points and have no healing surges left your condition doesn't change when you successfully make your Death Save (roll a 20).
I've been saying it before, SPENT healing surges can be used to represent "wounds" if you choose that "narrative." Your "wounds" don't magically heal because the Warlord inspired you. Your wound is now represented as the SPENT healing surge.
Because Healing Surges are not recovered until an extended rest, as a DM you can even force the issue. Keep the opposition on your heroes. They get no rests because their current surroundings are dangerous, or they keep getting their rest interrupted.
In this way, 4e does have a neat "narrative ledge" over 3e, although I would still tweak it slightly so it meshes better with the overall mechanics of whichever ruleset is being used.
I remember fondly those days when DMs would "tweak" the "rules" to fit what they wanted. Those were truly happier days, for me. And tweak you definitely should. Sometimes the "slavish" devotion to the "rules" is what these discussions end up revolving around.
I'll give a super simple "tweak" that does not in any way "destroy" the internal consistency of 4e, if your purpose is to have "wounds". After an extended rest you recover all your healing surges, but not all your Hit Points. If you were in fact "injured" before you started your rest, you will have to spend Healing Surges after the extended rest to recover those hit points. If the DM has already "narratively" decided on "wounds" he now still has them the next day. "Narratively" the spent healing surges are the "wounds".
I have even more "tweaks" that deal with short term and long term injuries here.