A messenger with Tor? Seriously, no matter how much of these apps/services they have come up with that make use of Tor technology, there isn’t any point for privacy advocates to live with that since it is over-protective. What Tor Messenger does is that it makes use of Off The Record messaging and allows you to connect to services like Google Talk, Yahoo Messenger, Facebook chat, etc.
There are better security related technologies that don’t go against the functionality, reliability and performance that you could have used better while going on in your daily computing activity. Just don’t use those technologies for bad things and you should be fine.