The male mage is the Wizard.
Anyway, Dwarf trailer translation:
0:12 With skin like rock and a thoroughly tempered body
0:16 this member of a proud family of the earth pulverizes everything.
0:22 This superhuman strength allows him to easily
0:25 lift and hurl even enemies that surpass his own stature.
0:30 When he skillfully mows down enemies,
0:32 he should even be a match for a thousand warriors.
0:37 Be a Dwarf and confront unknown enemies...!
(I changed 'become' to 'be' in the last line because I decided that 'become' sounded a little silly, but the final line is the same structure for all of them. Whatever...)
Anyway, in terms of class balance here's what I'm guessing:
Fighter - The tank. Probably has the best defense in the group. Which isn't to say he won't do damage, but probably not as much as some of the others.
Sorceress - Looks more agile than the Wizard (that air dash...), and has more varied spells. You see her doing some necromancy, freezing enemies, etc. Probably doesn't do as much sheer damage as the Wizard, though, and is likely pretty fragile too.
Dwarf - Similar to the fighter, but looks like more varied attacks to me. Probably does a bit more damage but has lower defense, which is not to say that he'll be a pushover or anything.
Elf - Fast and agile with a wide variety of attacks, including ranged attacks. Likely fairly fragile, though hopefully not as bad as the magic users. I'm not really sure how much damage she'll be doing, though...
Wizard - He's going to be the biggest damage-dealer of the group. He's slow and lacks the variety of spells that the Sorceress has, but all of his spells seem to be of the big attack variety.
Amazon - Who knows, haven't seen her trailer yet. Probably another type similar to the Fighter and Dwarf...
Personally, from what I've seen I'm most interested in playing as the Elf right now.