If I was Tendulkar, I reckon I'd still carry on.
He strikes me as being like that guy in the office who still works there even though he passed the retirement age a few years back; he continues doing his job because it's all the life he knows and the thought of not waking up in the morning and having a job to go to terrifies him.
Tendulkar's been involved in First Class cricket since he was 15 - he's spent 24 out of the 39 years he's been on the planet involved in cricket at the highest level. All of his other fab 4 contemporaries made their FC debuts as teens (and Ganguly his international debut at 19) but they would have had fairly normal lives as late teens/early 20s young men. Dravid, Laxman and Ganguly all made their Test debuts at the age of 23, by which point Tendulkar had been on the scene for about 40 Test matches and god knows how many ODIs.
Besides, Tendulkar has a level of fame and adulation above and beyond that experienced by any of his team-mates. They're all superstars in their own right, but you get the feeling that Dravid, Laxman and even Ganguly can have some sort of a normal life now that they're retired. Tendulkar, by all accounts, has to take to wearing disguises just to go to the movies and takes his cars out for a spin in the middle of the night because it's the only time he'll get some peace and quiet in order to do so. Given how iconic Tendulkar is in India, I can't see that changing once he's given up playing cricket. The life of a cricketer is all Tendulkar has known for almost a quarter of a century, and giving up playing cricket won't just allow him to lead an ordinary life all of a sudden.
Ricky Ponting might look at his kids, think to himself "yeah, I've had a good run as a Test cricketer, I can't really be bothered any more, I've been struggling to hit the ****ing thing recently, maybe it's time to move on and spend a bit more time with my wife and kids instead of ****ing off on tour for 6 months of the year" and decide to chuck it, but I don't think Tendulkar has that as an option, and his status as a child prodigy IMO means that he perhaps lacks the perspective to consider his life without cricket.