If there's ever a situation where you have to have a platform object pass through a solid object, it gets pretty messy. You have to make a sprite to take the place of the object and switch them out, and, well... setting the collision mode to none as you could do in CC would be very helpful with that.
Not a big concern, but it'd be much more convenient. <img src="smileys/smiley4.gif" border="0" align="middle" />