No it does not. There is already too much stuff that was added to this site that bogs it down and causes too many glitches now. And the site is continuously growing and needing more servers and bandwidth due to rapid growth. We sure don't need a bunch more problems by adding IM. While it might be fun to have, it is not worth the possible added hassles. Talk in PM or leave comments on profiles.
I don't find it necessary though.