The Unofficial MK3 movie page has updated with news from Robin Shou (who played Liu Kang in the movies), stating he will not be playing Kang in the new film, and it is in fact a prequel about Sub-Zero.

"I got the bad news. I won't be in the next MK. Apparently, Sub-Zero will be the new hero. How'd that come about? No body knows. As if my character never existed. The story supposedly takes place before Lui Kang's time. A prequel of prequel. I haven't read the script but the word out there was... bad."


http://mk3movie.mortalkombatonline.com/

So, I found it at Outworld. So Sue me.