You need two beamlines to dance and cause our existence to go askance. There's only going to be one tomorrow. Even if they start both beamlines, unless you intentionally cross the streams with our licensed nuclear accelerator, ain't nothing gonna happen. So unless Gozer makes an appearance tomorrow at the top of the ATLAS experiment and they need to banish him/her/it, we're safe.
Really quickly, on the topic of the LHC, when I heard about the statistically impossible possibility of destroying the world my answer came quickly;
"What are we going to do? NOT turn it on???"
We have reached the pinnacle of our understanding of the physical world. What are we supposed to do? Sit on our hands?
Of course, an honest assessment of my position would reveal that I don't really care if the whole world is destroyed. Meh. I want my anti-gravity and teleportation. An understanding of "dark matter" has promise in an incredible array of new technologies.
This is the next level, people.
This could be bigger than anything we've ever done AS A SPECIES.
Suck it up.
Drink a cocktail.
Enjoy the moment our understanding of the universe changed.