DiabloFans

http://us.battle.net/d3/en/calculator/demon-hunter#bYRPhV!Uge!aabccY
This build revolves around keeping enemies slowed with caltrops(hooked spines) and AoEing them down with a combination of bolashot, multi shot, and Cluster arrow. The only real drawback would be on single targets and the lack of defensive cooldowns. Although vault may beenough, as the difficulties increase to hell and beyond, I am not quite sure as to whetehr or not this build would continue to be as effective.
All that being said, this build should fly through normal and nightmare difficulties without a hitch.
-Freed

As much as all of us without beta keys would like it, blizzard won't do an open beta. It would be immensely fun to play with a ton of people; however, as said before, a beta is for testing not for everyone to try the game.

On a different note, I do see them doing some sort of free trial in the future, after the game is out, not that it helps us out now.

Quote from Reddaye

I can see a melee centered nature themed class. We obviously are short on melee compared to ranged...so it seems logical. Something like the druid (shapeshifting). Using the Werewolf and Werebear forms to give a different play style.

I completely agree here. This would fill the niche the game seems to be lacking imo. I would also like to point out that, as long as blizzard is good at separating build, we may see a character that uses more than strength. The druid for example could eitehr go caster or shapeshifter with INT and STR respectively.
As for the second class.... I have absolutely no clue haha.