We don't have video yet (UPDATE: It's here), but Joe Hoeffel will supposedly start running an ad in the Philly market soon that targets Dan Onorato and Anthony Williams. From the Inquirer (via GrassrootsPa):

Hoeffel today will introduce his first TV ad in the Philadelphia market, and it's a feisty one. It takes a slap at two of his opponents while also trying to introduce himself as the progressive choice in the four-way Democratic primary on May 18.

In the ad, Hoeffel sits at a desk in a high-rise building and holds a pair of pink flip-flops in his hand.

The script for the 30-second spot goes like this:

"Flip-flops are fine - for the beach. But as governor people need to know where you stand. Dan Onorato was anti-choice for years - until one day he wasn't. Tony Williams used to support public schools - now it's private schools. I have always supported a woman's right to choose and our public schools. And I have developed a detailed, comprehensive plan to help small businesses create new jobs. You want flip-flops - go to the beach. But if you want a governor who proudly stands up for our progressive values, then I'm your man."

Williams was first out of the gate with a negative ad, attacking Onorato on the economy.