Velocity and Direction Tags

Velocity Tag: An nbt tag for projectile entities, a replacement and upgrade to the motion tag. This would determine the velocity of a projectile, similar to the motion tag. it would look something like this: /summon minecraft:fireball ~ ~ ~ {Velocity:3.0}. The direction tag would be there to help out the velocity tag, specifying a direction. The point of this is so you can also summon a entity projectile where your looking (obviously, a way to use both ~ ~ ~ and ^ ^ ^ would need to be added), but I think this small change would be so helpful for command block users.