[Pitch] Parameter Packs

This motivation is exactly what I consider to be wrong: Features should be added when they fit into the big picture, and not in the by their rank in some wishlist.
Returning to an old comparison ([planning] [discussion] Schedule for return of closure parameter labels (+ world domination ramble) - #7 by Chris_Lattner):
You usually really want a roof when you build a house, but still you finish the walls first.