FWIW, The LLVM Project switched to C++11 (or the subset supported by a variety of compilers (Clang, GCC, and MSVC) with a horizon of about a couple of years ( http://llvm.org/docs/CodingStandards.html#supported-c-11-language-and-library-features ). Seems to be doing OK so far.
Exactly. I've found writing LLVM-styled C++11 to be pretty pleasant, and I'm skeptical that there are very many people for whom running a reasonably recent version of GCC, LLVM, or MSVC is a hardship.
John