The jury is still out on whether string theory will be relevant for Physics; although in the words of Edward Witten, if string theory would be wrong, "it would seem like a kind of cosmic conspiracy."
What seems beyond the shadow of a doubt is the impact that string theory has had and continues to have in certain areas of Mathematics; although to be fair, it is difficult to disentangle the impact of string theory proper from that of supersymmetric quantum field theory, since the two theories are so intimately linked. Indeed, supersymmetry is arguably the only testable prediction of string theory thus far.
[To be continued.]
In 1996-1997 there was a year-long programme at the IAS devoted to bringing mathematicians up to speed with string theory and quantum field theory. This gave rise to a two-volume set of notes by the participants of this programme.
Pavel Etinghof teaches a course on Geometry and Quantum Field Theory for mathematics undergraduates at MIT.
I believe that any effort to bridge the language gap between mathematicians and physicists is well spent.