I was concerned when I read about the revamped combat system, because if my reading into of the mechanics is right, they essentially nerfed both of my preferred character options. I no longer can use a shield as a fighter-mage type character, and if I can't block(technically parry) with a one handed sword, it's a little unbalanced(not to mention doesn't fit into the RP concept, which kinda kills the immersion). As well, I do not know if I can block with only a single one handed sword, and that worries me, because my other favorite concept is sort of an assassin type(which kinda nixes the shield). If I can't effectively play my concepts, it will ruin the immersion, and that will impact my enjoyment of the game. That's not to mention the ruining of the immersion from the fact that anyone who has even an inkling of combat training should be able to parry with a one handed sword, effectively or otherwise.
You can use a shield as a fighter-mage type character. You'll have a shield in one hand, and a spell in the other. What you can't do is have a shield in one hand, a sword in other, and still be able to cast spells; nor can you have a sword in one hand, a spell in the other, and still be able to block.
You can block with a one-handed weapon, it seems, but only if you do not have anything in your other hand.