For whatever reason/s you may like playing against bots, the new WLS CTF mappack is awesome. The Bot routes are so well done that they actually steal flags and get them back to base to score. Get it here WLS CTF Pack
Keep in mind that this is no where like playing CTF online.. but it is fun when servers are down, full and/or you need a CTF fix.
What a shame WLS has left JKII for UT2K3.