It will send messages to MSBT, SCT, or Blizzard's new Combat Text addon if available, and if not, it will create a seperate frame.
Bah, knew I'd get that comment. >.<
SCT has a "regular" animated frame and a non-moving message frame, this one sends to the regular frame. WitchHunt2 and others can send to both... so yeah, an option to do that would be great. :)