Certainly, Steve Jobs could sit on his hands, attend board meetings, show up at the Apple campus occasionally, and otherwise do nothing, for as long as life and breath remain to him. He could, that is, if he were someone else.
But don't expect more of the same from him; others are quite capable of carrying Apple's products and services forward, and Steve's time is too precious for him to be spending it on what others can do (except as he might find dabbling therapeutic).
With unique abilities come unique responsibility, and Steve's abilities are at least a rare combination, if not altogether unique, and are amplified by the tremendous resources his past successes have placed within his reach.
Moreover, he commands the attention of millions; even his offhand remarks are routinely widely distributed.
From where I sit, there's no telling what he will choose to do with all this, but I'm anticipating something insanely great!