I had a moment of panic when I read the headline on Entertainment Weekly’s website, but it’s okay; just breathe. Jon is not leaving the show; apparently he’s going to take the summer off to direct a film based on a book by BBC journalist Maziar Bahari, who has been a guest on The Daily Show. See EW’s story here:
http://insidetv.ew.com/2013/03/05/jon-stewart-daily-show-john-oliver-rosewater/
It was clear on the program that Jon had a strong reaction to Bahari’s experiences as a human rights activist, including his captivity in Iran, so his decision to collaborate with Bahari on the film makes sense to me. I’m also very happy that John Oliver is filling in for Jon. On the rare occasions when I’ve contemplated the unthinkable, I have imagined that John would be a good replacement for my fellow William & Mary alum. Here’s hoping the venture is a success for Jon and John!
Pop Goddess 
I’m definitely not looking forward to Jon’s absence, but I agree that Oliver is the best possible replacement. I do hope he tones his presentation style down just slightly. It works okay in a bit, but I’m not sure I would enjoy that level for a whole show (let alone show after show). A host should be a little more tone-balanced, I feel.
I’m just glad it’s not Samantha Bee or Jason Jones. I don’t have a very high tolerance for them beyond certain limited bits, either.
Likewise! Both those two grate on my nerves very quickly. I’m not much of a fan of John Hodgman, either.
Of his participants, Oliver is definitely the best choice!