As the developer of ChatBlade we don't know of any current competitors. Many MMOs can ship with excellent, hand rolled chat such as Rift or SWG, but other AAA titles such as Age of Conan or DC Universe Online release with broken chat and can lose subscribers due to this.
Before creating ChatBlade I worked on Chat for another MMO initially using IRC. The public IRC source I found at the time was terrible. Incredibly ancient C (so old the parameter types were put after the parentheses in the function declarations). A message would go in and sometimes take 5 minutes to come out, from a server across the room. If you go with an IRC base try and use a more modern release.
If you are interested in ChatBlade we can offer deferred payments or other pricing flexibility.
Full ChatBlade documentation is online so if you want to use that as an outline to roll your own Chat, feel free as well.