First: This post is about PvE only.

Second: I'm talking about info you can find here mostly: http://tamrielfoundry.com/#

And I have not been in the beta and none of my friends so I don't have any private info.

Looking at the various class toolkit we can see their is a lots of combination that seems to be possible. I think it is fair to say that all 3 (dragonknight, nightblade and templar) can wear leather or plate and go anywhere from tanks, to melee or range DPS. Even a bit of bow + melee mix seems possible.

But when looking at the sorcerer its not quite sure.

First their personal toolkit is all about "spells" and the way armor bonus works, going for some kind of battlemage set-up seems to be a bad choice.

If you choose to take some melee weapons and jump in the crowd using cloth, your spells will be powerfull but you your physical attacks will lack the armor bonus. If you wear plate/leather its the reverse, your spell will be weaker in order to make your melee attacks more powerfull.

Mixing both armor type just weaker both style.

Sure you could always join the fighter guild, become a werewolf and pick up every other "physical" skills the game offer to every class and, wear a full plate/leather, picking-up only the none numerical value sorcerer skills (dispells, root etc) but what would be the point ?

Doing so its just smarter to pick-up one of the other 3 class that will offer you even more bonus.

For PvP its totaly different. Since going in full plate with a sword and spaming long range spell (with lower damage due to no cloth bonus and less passive bonus) till someone reach your melee range to finish them with your swords might be totaly viable. But in a PvE group, its pretty safe to assume that going full damage set-up with a fewer CC,defencive and escape tools will be viable.