Debating realism in a Diablo discussion is a bit silly. In a game full of magic, demons, wizards, portals, and the like, is it such a stretch that the Demon Hunter wouldn't need to reload a crossbow? Collecting arrows/bolts in order to have a viable character (or being forced to find a replenishing stack weapon) is an outdated practice, IMO, and I am glad that the Diablo 3 team have seen it as such (unless you still need to search for ammo, in which case I guess I won't be playing the DH like I didn't play the Zon in D2).
To those of you who claim that the DH destroys the game: how mature of you. The devs didn't design the game to your ridiculous standards/expectations. Feel free to not play it rather than complain constantly about it on the forums. If D2 is your basis for what D3 MUST BE, stick with D2. There are people among us who feel that another evolution of the series may turn out for the best; from what the devs have shown, I am a firm believer that they are making good choices. I don't like everything they've done (far from it), but I can see where they are coming from. Overall, I feel they are doing an excellent job. In the end, this will probably be another epic Blizzard game in a long line of epic Blizzard games.