He looks so tired and frail. It's hard to imagine John Paul II sitting back in a rocker, whiling away the time watching daytime TV or playing dominos for the rest of his days. But there is the question of retirement itself.
Popes can quit and have in the past.
Pope Celestine V turned in his Keys to the Kingdom in 1294 after only six month on the job, a shorter stint than your average New York City schools chancellor's. There were others too. The resigned Pope would still be a cardinal and a bishop but would surrender papal responsibilities totally to the new Pope. Infallibility goes with the office, not the person, and would also be passed along to the new pope. John Paul is as you say weak and frail.