Just a matter of time. He'll make it to summer, unless things go really crazy, but I don't see him staying beyond. Levy obviously likes him, but lets be honest, Levy is hardly a sentimental kind of guy. If they fail to make Europe - which seems likely at this point in time - then he's gone for sure.
And then I think that's that for Mourinho at the highest level. Spurs was a gamble because it was the first time he'd taken a club that wasn't already a proven winner since Chelsea first time round, and that was with the backing of an open chequebook in pre-FFP days, so it was kind of different then. He needed to make it work to get a future job at one of the giants, but its gone totally wrong for him.
He'll always be able to get a job with a mid-table club of course, but not one of the big clubs. He might get a job at Inter again, that's probably the only destination. But the idea of him getting a job at PSG, Juve, or back at Real, is laughable. He should probably take a job as a pundit (which he's actually very good at) and keep taking the cheques for TV commercials.