Heh, 'twill be most interesting when Harry doesn't return and Dumbles finally twigs that Harry never went home with the Dursleys and could be anywhere (imagine the panic in Gryffindor tower when they realize they've driven Harry away (of course, they'll never take responsibility for their actions).
I will strongly agree with those above who suggest that a sequel, with the British wizarding world "desperately seeking Harry" goes bananas as they can't find him. It would be amusing if another country took him and helped him hide properly (perhaps they have schools that Albus denied the right to recruit Harry? There are all sorts of possibilities here). Personally, I'd love to see him get away with it and Dumbles have to deal with Quirrel et al. on his lonesome.