I like to imagine that if John Lennon were still alive, he would have become a truly transcendent figure--writing songs no doubt, but engaged in worldwide efforts for peace, justice and equality. Think Bono but much more respectable and influential. More like what Caetano Veloso is to Brazil but on a world-wide scale: civic leader, national poet-hero, voice of conscience.
I suppose it's more likely that John would have stayed out of the spotlight.
What do you think he'd be doing? What do you like to think he'd be doing?