SithAce_1
Sith test pilot
Just researching a little found this:
"Finally, one Sith Lord took his forces and retreated to the Unknown Regions where they would bide their time, and wait. These True Sith later known to be the survived Sith Empire apparently still held on to Malachor V as a teaching center." This was after the Sadow's war on the republic.
And this just after the defeat of Exar Kun:
"The Old Sith Empire continued to survive in obscurity in the unknown regions, still lead by the same Sith Lord who had escaped the Empire's destruction centuries before during the Great Hyperspace War."
So to who and what the new Emporer is, is to be revealed in game and on the swtor website. But from what I can tell there is a lot of room in star wars for this new myth. Remember no one knew who anyone was back in 1977! Hell I was only 5yrs. old then. I think its the creators and the fans who shape this whole thing called star wars.