On one hand, last week Fedor looked bored/demotivated/depressed even before the fight. He lost his Tyson effect too. Plus the fact that he never seemed to love fighting like most guys - he said he never dreams about fights nor likes to watch them.
On the other hand: he still has fans, people would watch him. And come on, would we be discussing whether any other fighter should quit after only two defeats?
So it boils down to whether Fedor is motivated. If he finds the motivation from the best years of his career then I believe he could again dominate seriously big guys. But how could he do it? Religion doesn't seem to help him.