The rule basically makes the league's ad hoc ruling from last August--when AJ Trapasso nailed the JerryTron with a punt in a preseason game--more official.
The record-breaking video-board proved to be a non-issue in 2009, but the NFL isn't wont to leave any stone unturned, when it comes to competitive policy. So, with that in mind, presenting the newest NFL rule that you already kind of knew:
If a loose ball in play strikes a video board, guide wire, sky cam, or any other object, the down will be replayed. Instant replay can be used to determine if, in fact, the ball struck the aforementioned video board guide wire or sky cam--essentially, the do-over rule that induced so many groans last summer is back, and more official.
Also on Wednesday, the league passed a rule declaring the play to be blown dead, should a ball-carriers helmet come off; which is good for player safety, we suppose, but bad if you're a fan of helmet-less shows of outstanding manliness like this one, afforded us by Jason Witten a few years back in a Sunday night game against Philly: