SureAI

The game ends when the MQ ends, so enjoy the well crafted world around you and the numerous side quests it offers. That is all.

They should make it so that you can continue just like you could in Nehrim.

They said, and so it is, that it make no sense in the Lore that ypu can continue the game after the end. #Spoiler
But this SurAI said in all pre-release infos too...
And by the way, why everyone should rush the story... you can explore so much land... :3

There is a dialogue box that informs you explicitly of the 'point of no return'. So even if you should have rushed through the MQ up to this point, you still get the chance to do some exploring and finish your sidequests. Unless you ignore the warning, of course. Without spoilering, sometimes end simply does mean end.