Ok, here is mostly speculations and putting small pieces of information together.

What we know is, that there will be 8 new hereos. We also know that there will be 4 classes and each class can take two routes. We all know about warrior examle when warrior can be berserk or knight.

So, 8 heores / 4 classes = 2 heroes per class. Then 2 heroes per class / 2 subclass. So i can assume that every single hero in new box will be representative for each sub class in the game.

Now, lets sum up information about heroes.

We all know Leroic of the book, (mage) and Widow Tarha (possibly a healer... maybe mage)

What left is two miniautres which are shown in that gaming magazine (link here : http://boardgamegeek.com/image/1249367/shnar )

Those two are definetly payable. 

That big guy with mace, lets call him Billy the Mace (warrior - knight) and small guy with knife, lets call him Oliver Twist. (LINK: http://www.gametrademagazine.com/Home/1/1/58/591?articleID=117244 )

I will ignore characters printed on box due to the fact that first descent first edition box have characters from tomb of ice on it.

What is left are that beautiful Elf Lady (scout), Dwarf (Fighter Berserker) and some blue character which can be seen on table on http://boardgamegeek.com/image/1249367/shnar

Blue = Healer of mage.

Now, lets summarize

Fighters : Billy the mace (knight) X Dwarf (berserker)

Scouts : Elf Lady (archer) X Oliver Twist (rogue/assasin?)

Mages : Leroic of the book (sage) X blue guy on the poster (elementalist)

Healers : Widow Tarha (Shaman) X Great Unknown (bard or priest)

And i bet my overlord mug that i am 50% accurate :)

What is bugging me is which class will be guys Battle Mage Johnas or other characters which are not pure class oriented :)

 Well, i was hoping for edit option.... sorry for the format guys :(

I'm pretty sure the sub-classes will be optional.  ie: Any "Warrior" class character could choose to go either "Berserker" or "Knight" when he reaches the appropriate point in the character building system.  There may be some characters better suited to one or the other, and it wold certainly make sense if the 8 heroes i the game showcased each sub-class, but I sincerely hope they don't "need" to go one way or the other.

One of the most boring aspects of 1e was how each character had an "obvious" best build that one would be a fool to turn his back on (barring those heroes with no specialization, of course, who generally sucked.)

 I agree, that they will be optional. But as you mention, some heroes will be destined by their abilities or appearence to take one sub class.

One-Fist as a knight? :)

But if one look at the changes in abilites for Landrec, Sir Valadir and Johnas the Kind, he must thinks, maybe the FFG are making changes just for the purpouse that every hero will be suitible for both subclases. 

Well,

with new preview, we recieve new information about our heroes :)

Each hero sheet have a colored "gem" in the middle top of their character sheet. Colours are Red, Blue, Green and Yellow.

Red = Warrior

Blue = Helaer

Green = Scout

Yellow = Mage

Lets update my old speculations

Warriors = Dwarf guy with Axe (representative of berserk subclass) X Elf girl (representative of Knight)

Helaers = Billy the Mace (representative of Paladin class?) X Widow Tarha

Scouts = Oliver twist (representative of rogue/assasin) X Great Unknown (no figure, picture or character sheet yet seen, archer subclass?)

Mages = Leroic of the Book (rune master) X Girl with a snake (elementalist)

 - Ok, great hole in my speculations, there are three character sheets with yellow gem on them (widow Tarha has a yellow gem) i hope that with new previews, this hole will be leaped over :)

Skill descriptions for most of these heroes are unreadable but you can still substract or guess their statistics. Great difference is, that we can see a "10" wounds on some character sheets instead of typical 8,12,16 wounds. ( i know about 20 wounds issue of Hugo the Glorious but i, as a overlord, will just pretend that this kind of guy do not exist). Also the dwarf guy have a 15 wounds on him? ( i need a bigger glasses or better picture to be sure).

Well, i hope that in new descent will be a 2:2:2:2 class oriented heroes, not 2:2:1:3 class oriented heroes. 3 mages is too much :)

Jafix said:

Hum...for me it's obvious :

8 heroes in the box --> 2 heroes/archetype.

And so the 2 mages are Leroic and Widow Tarah.

(for me the color of the symbol on the heroe card tell the archetype : so yellow = mage)

The cool thing : it seems to be a male and a female per archetype,and that's great i think.

Where is "the girl with the snake" ?

Jafix said:

Perhaps the gem is nothing to do with class - maybe it's a measure of what the overlord gets when he kills a character...

 Girl with a snake can be seen on leaked pictures of chinese version (right player on the picture), then on Game Trader Magazine (her hero sheet is under widow thara hero sheet) and her figure can be seen in newest preview (iam just gessing here, that stuff around here looks like a fox toail or fireball)

Colour gems... well, most typical wizards have yellow (leroic of the book, landrec the wise, mad carthos and Widow thara), green (ronan the wild), red (sir valadir, dwarf guy and elf girl in ver.2), blue (Billy the mace, Jonas the kind), if i see a different colour on different character type, i will gladly say that you are right, those Three wizards in second edition are creeping me out :)

All three yellow character sheets can be seen in previews and leaked chinese version of descent 2E

Jafix said:

it's hard to tell if it's the same yellow on leaked chinese version...

or maybe there's only one healer in the box (and and then 3 caster?)

Aw.....so many questions...release the game ! :D

i don't have the v1,and i really can't wait the v2...

I would guess that game mechanic will be still the same for chinese and american version. Possibility of three wizards is keeping me away from sleep :)

the image on the official has changed...

now it's Widow Tara near the elf :

 Billy the Mace is Widow Tara at weekends.

 A real Dwarf Fighter (a Dwarf looking like one, at least) seems to enter the fray...That's reason enough to take 2nd ed to me! I'm moved...he's even got a two-headed axe...my favourite...

Bleached Lizard said:

I hope that there will be 2 for heroes per crchetype, but looking at all those pictures I'm a little bit confused.

The way I see heroes is:

Warrior  (red) - the elf Sudra & the dwarf with axe

Scout (green) - the halfling with a knife  & unknown

Healer (blue) - the blue man with a mace & a woman with staff (see the minis pics from 1st preview)

Mage (yellow) - Leoric Of The Book & Widow Thara

So there is one missing. But looking at the pics I can tell that we are missing a scout woman. The pic that shows the 3rd mage is in my opinion from a very soon state of the game, besides we do not see it clearly. Let's wait for the next preview maybe it will clear thing up.

There's one more thing that I see - in every archetype there is male and female hero - I love it. I always thought there there is a too small number of female charactres in this game.

Jafix said:

The only major difference between the two versions is that an hour after playing, you'll be hungry to play more of the Chinese version...