It is indeed an "important" point in the battle between ID an ET people, once more, the argument didn't stand long.
The IC argument was dealt the death blow before Behe was even born. This is a quote from 1918:
"Most present day animals are the result of a long process of evolution, in which at least thousands of mutations must have taken place. Each new mutant in turn must have derived its survival value from the effect which it produced upon the "reaction system" that had been brought into being by the many previously formed factors in cooperation; thus a complicated machine was gradually built up whose effective working was dependent upon the interlocking action of very numerous elementary parts or factors, and many of the characters are factors which, when new, where originally merely an asset finally become necessary because other necessary characters and factors had subsequently become changed so as to be dependent on the former. It must result, in consequence, that a dropping out of, or even a slight change in any one of these parts is very likely to disturb fatally the whole machinery; ..."--"Genetic Variablity, Twin Hybrids and Constant Hybrids, in a Case of Balanced Lethal Factors", by Hermann J Muller, in Genetics, Vol 3, No 5, Sept 1918, pp 422-499.
The ironic twist is that we should actually expect to see IC systems if evolution is true.