ok so in the AD&D Deities and Demigods, it outlined the difference between a spirit and a soul. In essence elves, dwarves, and other demi humans did not have souls (and could not be resurected but could be reincarnated) and in essence never really moved on eternally to the higher or lower realms (always they would return to the prime or the fey, etc.) I really kind of liked this distinction to the humans, in our games we expanded on that premise to say that human souls provided greater power to their deities (to explain why there were only a hand full of demi human gods/goddesses, as well as explain why palidins had to be human, and to help explain how human cities and settlements could survive in a world filled with wandering monsters)
since I'm not too familiar with 3 or 3.5 and I never read too much background fluff in 4th... has this been changed? is it still the case? if not I'd sort of like it to going back to the elves have no souls days.