WWP wills still be a good way to drop off vulnerable shooty units for a first strike or sideshots where it realle hurts. The ability to create an attack vector at will should not be underestimated now that casualties are removed from closest to furthest.
I've always used thd WWP to enter shooty units and jetbikes and at most a single unit of wyches so there won't be that much difference for me other than my opponents will have a tougher time shielding their important dudes.
However if the WWP is FAQ'ed to allow assaults, it will be godly!