One of the problem is that none of the Trac developers seem to be using 2.3 anymore.
Jonas, you mentioned on IRC that you couldn't run a buildbot for 2.3 as it doesn't support virtualenv. I'm not familiar with buildbot, so I don't know if the requirement for virtualenv comes from buildbot usage or if you just used virtualenv to setup the test environments for 2.4, 2.5 and 2.6. If it's the latter, then I think you could nevertheless have a test environment for Python 2.3 without virtualenv, as we have to test Trac 0.11-stable only with that version.
