8 is a nice round number. Quality over quantity is what I'm praising too. I rather see few well writen intresting companions than lots of generic mercs. Besides we have the adventurer hall for that, don't we?
In any case don't you wonder which classes of those companion are going to be. Weren't there a ranger, a warrior, a priest. a monk and a wizzard in the concept arts? Not that those were necessarily all companion, but it still makes you wonder the party composition.
Well in any case when I think about the class variety, any balanced party of adventurers needs atleast.
-warriors
-magic users
-stealthy types
Thus I have placed the eleven classes in three major groups:
1) Fighter classes: Warrior, Barbarian, Monk and Paladin
2) magic user classes: Wizzard, Druid, Priest and Cipher
3) Stealth classes: Rogue, Ranger and Chanter (to me it sounds like a bard whom is a mix of magic, stealth and combat)
Now this obviously doesn't mean that classes couldn't overlap eachother. I recall obsidian saying that you can have a wizzard in plate armor or a priest for example who is more intrested in combat arts rather than spells. Still to me those 3 character architypes give some idea where obsidian is going with companions' classes. Also because combat skills are seperated from non combat skills in leveling, it also offers you more options.
So my quess that we are going to see 2 companions from each gategory. From group 1 I'd pick warrior and monk. Warrior because well its a classic choise and monk because monks are freaking awesome
From group 2 the classic choises would be wizzard and priest. I personally would like to see Cipher as companion since, the class sounds like a very unique concept. Or heck why not replace both classic choises? Druids are much cooler than priests anyhow. "This city is a blight on the landscape. Better to have let the land grow wild!"
From group 3: Rogue is the most obvious, because if the player isn't a rogue, who else is going to do all the backstabbing. Every classic rpg has had a ranger companion too. And the concept art seems to hint that direction.