I looked back and found one of these threads a page or two back, but it was pretty outdated, so lets get another up. I've always been a fan of taking the path less traveled by, and blizzard has always given me the opportunity. Whether it was Diablo II, Warcraft III, or WoW, there was always something to do that was still viable yet deviated from the norm. The melee demon hunter might fill this for me in Diablo III when I am tired of playing normally.
So lets talk about it. A melee demon hunter, or more accurately, a demon hunter that wields a melee weapon, has a smaller window of skills and abilities that he/she can use. The removal of the passive "fundamentals" almost requires you to be using grenades more. For those who don't know, fundamentals was a passive that increased the damage of your basic attack by 100% and granted 4 hatred. But now that that's gone, the melee demon hunter will need to be tossing grenades and using a few other discipline spenders to keep his hatred up, which is just fine. Many abilities cannot be used, such as multishot, hungering arrow, cluster arrow. Infact, I'm not sure we know which abilities can or cannot be used, for example strafe. Strafe shoots arrows at enemies, but one rune makes you throw knives instead of arrows. I think it would be absurd if blizzard required you to wield a bow or crossbow in order to throw knives. Also rain of vengeance, some runes shoot arrows and other have shadow beasts. But in the end, there is still a good amount of skills that a melee demon hunter will be able to use.
What are the pros and cons?
-Solid damage with a 1 handed weapon
-High defense, granting you access to both survivability and some high damage skills requiring close range -You'll be doing something a bit different than everyone around you
-Most abilities % weapon damage abilities like fan of knives will do more damage than if you were wielding a bow or handcrossbow.
-You get to use a shield (more on this in a sec)
-lose your ranged power
-more restricted in the abilities you choose
-have to throw grenades
-might lose some dps, but we don't really know about this one yet. You might deal more
I was looking through the items on the official site, and it looks to me that the best setup might be a one handed mace + shield. Why a mace? Because not only does it have higher dps than any other weapon wield-able by the demon hunter besides the 2 handed crossbow, it has a very high max damage. With high max damage comes hard hits by many abilities, especially the ones requiring melee range.
Now the cool part. The Shield. The shield is an interesting thing because there is no real "shield wielding class". Any class CAN use a shield, but none have to. In Diablo II, almost every class used one, in Diablo III, the norm might be to NOT use a shield. A shield has HUGE armor, around double or triple the amount of any other piece of armor that you wear, and as a bonus you get a chance to block damage. It boosts you're ability to survive by a solid margin, and will allow a class like a demon hunter to get in peoples(or monsters) faces. Since not many are using it, and it is pretty awesome, the demon hunter might as well pick one up. Grab one while its hot.
I don't know if the melee demon hunter will actually need to be hitting things with his mace, but what it DOES do is give him good damage for his abilities and allows him to hold a shield.