Dimitrios Apostolou proposed on Wednesday to the GCC development list Change default BOOT_CFLAGS for release builds.
His proposal is to introduce a "make release" mode for GCC that will build GCC in the fastest yet stable way possible. For example, he's thinking of at least having GCC build with --enable-checking=release BOOT_CFLAGS=-O3. In his opinion he definitely wants -O3 by default for the BOOT_CFLAGS, but he also talks about possibly enabling LTO (Link-Time Optimizations) and whatever else. BOOT_CFLAGS allows for non-default compiler optimization flags to be used during stage two and stage three of compiler builds.
We'll see what happens and whether there will be this new release-optimized mode for GCC 4.8 that focuses on stable performance advancements. Anything to enhance the compiler's performance by default while still being stable is certainly welcome.