Hit points, hit points, hit points... I feel that at this point in the stage, hit points really need to be renamed and rebranded. Yes, I know they're a sacred cow and they aren't going away any time soon, and yes, I like the mechanic because it's simple, cinematic and abstract, but they really need a new name! Over the past couple of editions, we've been moving away from the "hit points are physical damage" model, although D&D never completely divorced them from the concept. At this point, though, we've reached the point where hit points represent everything - damage, fatigue, luck, divine favour, and morale.
Once you get your head around this basic truism, all the random damaging and healing effects suddenly make sense. Why does the monster take damage just because he attacked someone other than the paladin challenging him? Morale; he's backing out of a fight and that weakens his resolve. Second Wind? Watch a Rocky film. It's all cinematic, and it works. Just, whatever you do, don't think of it as physical damage.
In spite of my general misgivings about 4e, this is something I'm rather grooving on. I can't wait to use my own version of Robert Fisher's injury table in my own games, as I think it manages to do something very similar, by driving home the idea that losing hit points doesn't necessarily mean getting hit. Which would be helped along a lot by changing the name of the "to hit" roll, too.