Don't panic, he hasn't left the country to go and run Apple, but he has taken a sabbatical to become Pope for a day.
Pope Innocent the 10th that is - anything else would be marginally ridiculous.
Steven tweeted in the morning that he was sitting for a portrait painting to be done by a reformed forger - and attached a picture of him prepared in his robes, sitting, waiting (and presumably tweeting) in a courtyard.
For a bit of fun, I decided I'd have a go at recreating Valasquez's portrait of Pope Innocent using the picture Stephen posted. This was created with oils with an impasto effect, using a pallete to match the original painting.
Visit the gallery if you'd like to buy a high resolution download or print of this image.