the way he described it is like the combination they use skills in will be important.
he said they will start out casting spells from range with cast times, then enter melee range for sword attacks, then go back to casting for chainspells

it honestly sounded to me like it will play a lot like monk, just instead of side and back it will be going between range and melee
More accurately it's going between casting and fighting but by the video the sword skills may just induce the melee/range cycle automatically

perhaps along the lines of spells will give you an "empowered sword skills" buff and then sword skills will give you a "chain spell usable" buff type of deal
and the utility side is apparently limited healing(one spell on a cooldown?) and a battle res