As you probably heard already, we soon will switch over to gcc 4.1.

This means, unfortunatley a flag day for sparc64, since a few corner
cases in the sparc64 ABI have been fixed in gcc. See:
http://gcc.gnu.org/gcc-3.4/sparc-abi.html.

The base system seems to be mostly fine, i.e. no problems have been reported
mixing in-tree libs (and shared libs) compiled with gcc 3.3 and binaries
compiled with gcc 4.1. But there has been no audit for the cases documented
in the above URL, so no guarantees.

The recommended update procedure is: after upgrading the base system to 
gcc 4.1, recompile every installed pkg from pkgsrc.

Martin