Guppy, I guess you beat me to the punch while I was typing. I agree with what you're saying except for one small thing:
"You want to know what's going to happen if you push the power up and fly to the maximum design speed? Nothing."
Probably true, but keep in mind that Vd is demonstrated on a relatively new aircraft with control surfaces rigged to production tolerances (the extremes, to be sure, but in tolerance nonetheless). If one were to try the same on a bird that's been in the fleet for 20 years, there's no guarantee that you wouldn't encounter flutter at a lower speed due to mis-rigging, excessive freeplay, and reduced airframe rigidity due to fatigue.
Not to say that anyone here is foolish enough to try it, but I'd still hate to have the impression that exceeding Vmo is no big deal.