Wouldn't be surprised if he walks. Doesn't tend to stick around at a club for too long of a period.....
That's because he's always had reasons to go on, though.
He went after Porto won the Champions League - he couldn't have done more for the club, ever.
He went after he couldn't get on with Abramowitch anymore at Chelsea.
He went after he won the Champions League with Inter - same here as with Porto.
Can't see him leaving Madrid before he's won the Champions League and league with them (I think he's got a great chance of winning both this year). If he did, he'd admit defeat - not something Mourinho would normally do.
I reckon that if he wins the league (and/or the Champions League), that's essentially job done for him.