I have seen videos on youtube pointing to hammerfell or high rock.
High rock definitly fits with the geography, but i really can't shake the feeling that if this game is going to be released 5 or 6 years from now, all those regions will have been explored in the elder scrolls online. For me, i think that reduces the hype factor. By that time the MMO will need more source material aswell. So, i still believe this will be a new continent.
If not, it definitely looks like high rock.