If he had any pride he'd resign. As it is he'll probably stay on until Brown gets in and then 'retire' - collecting a big fat pension in the process.
The office of 'Deputy Prime Minister' is completely pointless anyway when we all know the Chancellor is due to take over in the top job any time now. They've let Prescott coast for years because he's the only relic of Old Labour left; a bit like that period in the early nineties when they couldn't think of anything for Ken to do in Corrie but didn't dare sack their only original cast member.