gcc currently defines release criteria for gcc3. See http://gcc.gnu.org/gcc-3.0/criteria.html. For ix86 Debian is proposed as primary evaluation platform. For sparc and alpha, Ben Collins and Chris Chimelis volunteer to evaluate gcc3. Currently we do not have feedback from the other architectures (besides ix86). Please have a look at the debian-toolchain archive for the past discussions, if you consider to evaluate gcc3 for "your" platform.