Mortal Kombat: Special Forces is the next Mortal Kombat game by John Tobias. It is a prequel like Mortal Kombat Mythologies: Sub-Zero but since it is a totally different game the working title is MK: Special Forces.
Videogames.com had an interview with John Tobias on MK: Special Forces. It had a ton of info on the games as well as a little on MK5 and MK: Dreamcast. Check it out by clicking here.