No. It works the same basic way as in 3.x edition.
When you throw down a fireball in 4e you roll the damage. Then make an attack roll against everyone in the area. Those whose Reflex defense you hit take full damage, those you miss take 1/2.
It is exactly the same number of rolls as in 3.x, except that the caster makes the rolls instead of the target. Thus all the rolls add the same bonus, so it probably will go faster.
When you throw down a fireball in 4e you roll the damage. Then make an attack roll against everyone in the area. Those whose Reflex defense you hit take full damage, those you miss take 1/2.
It is exactly the same number of rolls as in 3.x, except that the caster makes the rolls instead of the target. Thus all the rolls add the same bonus, so it probably will go faster.