Matthias,
I'm not sure. I know I was told that hppa was okay. Also from my
conversations with Jakub it appears i386, ia-64, alpha and sparc32
should be fine. So I would suggest we focus on checking the status
of arm, hurd-i386, m68k, mips, mipsel, s390 and sh. I'm not sure
how many of those arches have even had glibc 2.3.1 built on them.
Jack