Martin: I'll wait until after 3.4 is branched to commit to default, and make sure I have some time to pick up the pieces when I do :). The buildbots should be fine, though; external-common.bat is patched to pull in the tix sources as well.
issue15968_tix.svndiff will need to be applied to http://svn.python.org/projects/external/tix-8.4.3.x and be tagged as tix-8.4.3.4 before changes are made to the cpython repo, though, but I don't have access to svn.python.org (nor enough experience with svn to be comfortable making the change). Could you possibly do that for me?