The GCC 3.2 release is now available. A primary objective was to stabilize the C++ ABI; It is believed that the interface to the compiler and the C++ standard library are now stable.There are almost no other bug-fixes or improvements in this compiler, relative to GCC 3.1.1. More detail about the release is available here .
There are some discussions in the qdn.public.qnxrtp.devtools group about the gcc3 availability for QNX. You are encouraged to join that discussion if you use C++ in QNX6.