Well, after of more than 30 years, string theory is in a died way.
Notinhg has been derived (in a rigorous definition of term). There is no derivation of standard model, there is no derivation of black hole entropy, there is no quantization of gravity nor derivation of Einstein general relativity, etc.
What is today rigorously derivable from string M-theory: nothing.
String theory does not unify the forces, does not explain the families of particles, not explain macroscopic 4D spacetime, is not full compatible with Einstein GR, nor predict the masses, nor the coupling constants.
String theory does not solve the renormalization problems of quantum fierld theory, does not explain the big bang, nor inflaction nor mistery of cosmological constant, nor explain why universe look 4D, etc.
The mith of prediction is that, a mith. Very recent work has showed that there around 10^100 vacua and terefore all predictive power of string theory failed. Stringys looked for a miracle the last 3 years. This year a number of results have laready shows that one cannot predict nothing from string theory. Therefore there is no theory.
The number of people believeing in string theory is decaying at a high rate. This year Witten plans to do no significant work in string theory research. He now is working again on QCD.
For more information (do not exhaustive and at a nontechnical level) I recommend to interested reader
www.canonicalscience.com/stringcriticism.pdf
It is "old" and does not include very recent work in the form of "no-go theorems".
"Even so, the study of these vacua has become more and more popular over the last year or two, with many arguing that, no matter how big the number is, at least it's finite, so you have improved over the standard model, which has continuously tunable parameters. This argument was made in the panel discussion at the Perimeter Institute a month or so ago. Also, a finite number of vacua allows you to study their statistics, by assigning a weight one to each possible vacuum state and getting a probability measure by dividing by the total number. You can then engage in wishful thinking that this probability measure will be peaked about certain values, giving a sort of prediction." "The new paper gives a construction of flux compactifications of type IIA string theory, and in this case the authors find an infinite number of possibilities. This should kill off any hopes of extracting predictions from string theory by counting vacua and doing statistics."
"With this new result, the infinitesimally small remaining hope of getting predictions out of the string theory landscape framework has now vanished. It will be interesting to see if this slows down at all the ever-increasing number of string theorists working in this field."
The may 23 a new string paper by Dine appeared.
The second paragraph of the paper admits that the infinite number of states destroys this research program, but deals with this by saying that the author will just ignore the problem for now:
"If this (infinite number of states) is true, many of the ideas discussed in this paper will have to be reconsidered.... the discussion of this paper will be predicated on the assumption that the number of relevant states in the landscape is finite and naive statistical ideas can be applied."
This is usual string research working model. Make hypotesis A and obtain conclusions, if it is shows that hypotesis A was wrong simply ignore it. This is the reason of that after of more than 30 years of intense study and public claims, string theory has done exactly nothing.