Drudge has links summarizing the various jokes:
“Remember when the country rallied around you in hope for a better tomorrow? That was a good one.” – Kimmel.
“There’s a term for President Obama. Not two terms.” – Kimmel.
“What’s the difference between a hockey mom and a pit bull? A pit bull is delicious.” – Obama.
“I have not seen ‘The Hunger Games.’ Not enough class warfare.” – Obama.
Update: Jim Treacher tweets, "I win." Yes he does.