I think that it is obvious the you are going to fulfill some Elder Scroll prophecy and become the Dragonborn, similar to the Morrowind style of potential prophecy fulfillment..... except with awesome graphics and dragons. There is no way that Martin is coming back, he wasn't even that cool. The Champion of Cyrodiil is dead, and the Nerevarine is most likely still in Akavir (although he won't die of old age because of the Corprus, so if any he would be coming back).

It's quite obvious, it's the Adoring Fan.

I think Dovahkiin is the player because that's the vibe I got from the trailer so I'm just gonna go with that until we get info next month.