Using C++ in GCC is OK
The GCC Steering Committee has approved the use of C++ in GCC, according to this message. Although the reasons behind the decision were not clear, but it’s probably a decision to make GCC framework more modular, by leveraging the C++ features. As GCC has become the mother of compilers, this decision could have great benefits later on. Have a well-defined interface, and hook in new languages via virtual functions, why not? And the many data structures, containers, algorithms, etc, which are readily available, could help to clean up the GCC code base quite a bit.
The message stated that not all features of C++ will be used, not initially anyways. But the question would be, how are they going to leverage all those nice standard C++ libraries?
And the bootstrapping code would be in C++ too? That would be fun to see.