I've said it before and this just goes to confirm it (at least in my own head) - Colbert >> Stewart. Jon is still pretty funny, but it seems as though he has too much to lose, and that affects his performance. His schtick is getting repetitive and too blatantly obvious. Subtlety is much more humorous, IMO.
Colbert started very subtle with his show, and has now put it in overdrive and is steamrolling the administration, and often times, his own audience. Plus, while his interviews are often hit-n-miss, even his worsts are 10x better than Stewart's 10-minute public ass-kissings. The Colbert Report replaced The Daily Show on my Tivo's Season Pass several weeks ago, and I've yet to regret it.
That said, let us remember that this *was* the White House Correspondent Dinner - an event that often has humorous overtones, even at the expense of the President and the Media. Colbert definitely went both feet in, but this wasn't exactly an unheard-of type of address. You guys talking about "spitting in Bushler's face," have, unsurprisingly, missed the point entirely.