The LHC will, at best, tell us that String Theory is wack. At worst...it won't tell us anything about String Theory.
As far as I am aware, while String Theory DOES make testable predictions, the problem is that none of these predictions, in part or as aggregate, can prove String Theory feasible.
In fact, in its current form, String Theory is quite flexible and can be modified to fit a vast amount of distinct observable states.
No theory is 100% sacred, nor should we enjoy that...I wouldn't have a job otherwise. But the utility of theories is really the discerning edge that science uses...Newton's theory of gravitation predicted the motion of heavenly bodies for a couple hundred years before any discrepency became noticable...and a Newtonian knowledge of gravity provides us with powerful tools...with it, for instance, we were able to navigate space well enough to land men on the moon; a feat that would have been considerably harder without mechanics and gravitational theory under our belts.
The problem, then, of String Theory is that...it does nothing.
Good ole' Max made a shot in the dark and said energy might be quantized in special cases, Einstein said it always is and confirmed it...and in less than fifty years, we had more quantum devices than we could shake a stick at, not least of which is the laser and, later down the road, the semiconductor transistor.
Oersted suggested that electricity and magnetism might be unified phenomena, and within a year Faraday had designed a simple, homopolar induction motor.
String Theory, in contrast, not only hasn't been confirmed or verified in the least...but it's not even clear what we would gain from such a verification. Hence, "Okay, what would that imply?"
I'm not trying to bash the theory, of course...even if it fails outright, the progress made in other branches by simply trying to validate String Theory is worth the failure. And perhaps, in time, we will find uses for it.
Perhaps I can shed some light on WHY String Theory is so ridiculous, however...Edward Witten, the leader of the so-called "second superstring revolution" (physicists need a better naming schema) is, probably, the most brilliant mathematician alive today. And, if I know anything about mathematicians (and I should, I'm quite a mathophile myself), it's that we enjoy abstracting everything to the extreme. Which is perhaps why String Theory is so polarizing, and so slow to be verified or utilized...because to even consider working with it, you need to be a brilliant mathematician...but if you're a brilliant mathematician, you'll probably care more about the abstract beauty of the theory than the gross, practical applications of it.
By the way, I absolutely love this comic. Great job.