Note that Steve wrote this in 2004 which, based on Steve's estimate of expansion rate, means that Amazon may have over 100 million lines of C++ code by now. As a point of comparison, Notes/Domino R6.5 (a complex beast) was documented as containing just under 20 million lines of C/C++ code. Compare that to some other estimates of size such as Windows XP's 40 million lines of code. What exactly is in Amazon's 100 million lines of C++?
That's a brick wall being approached at a pretty high rate of speed, IMHO. Forget the language - 100 million lines of anything are simply incomprehensible.