@Gervaise
I don't think it would be a problem if all three heroes are mages. In fact, it would be pretty funny that three of the greatest heroes of the Dragon Age belong to the group who is supposedly responsible for all of Thedas' woes.
Random NPC: Curse mages! Curse them! They cause nothing but trouble!
Mage!Warden: Umm, hello?
Mage!Hawke: There's gratitude for you.
Mage!Inquisitor: By 'trouble' you mean 'save the world'?
This is actually the theme behind my primary playthrough of the dragon age games, though half of it is a side-effect of the fact that I adore mages and always play them first. I like to call them the "Magi Heroes of the Dragon Age".
Also, hey, guys. I've just been quietly lurking here, don't mind me. Solas seems to be very interesting, especially given my love of ideas and myths (which he of course shares). Though, I must say, him being a female elf love interest makes it far harder for me to figure out who my female elven mage is going to go for. I suppose the choice will simply be hers when the game comes out.