Tom Petty [ tickets ] and the Heartbreakers have rolled out their North American summer tour, which will visit arenas, amphitheaters and festivals across the US and into Canada through late August.The outing is three shows in, with the next stop being a two-night stand in Philadelphia this Thursday and Friday (6/5-6/6). Since the original tour announcement, a second show was booked in the Boston market and a few festival performances were added to the itinerary: Milwaukee's Summerfest, Denver's inaugural Mile High Music Festival, San Francisco's Outside Lands fest, and the Pemberton Festival in British Columbia. Veteran singer/songwriter Steve Winwood is supporting the trek, which is detailed below.The road trip came as a bit of a surprise, since Petty had previously told a reporter that his 2007 tour to support "Highway Companion" could be his last."Highway Companion," which surfaced in the summer of '06, marked Petty's third solo release and 18th overall career album. The set debuted at No. 4 on The Billboard 200, making it the singer/songwriter's highest-ever chart debut. Petty also recently reformed his pre-Heartbreakers outfit, Mudcrutch, with original bandmates Tom Leadon and Randall Marsh, and longtime Heartbreakers Benmont Tench and Mike Campbell. The group released its first-ever full-length album in April, and the self-titled set snagged the No. 8 spot on The Billboard 200. The musicians supported it with an April trek across California.In addition to a recently re-released greatest-hits package, Petty and the Heartbreakers have been celebrating their 30 years of rock-and-roll history with the box set "Runnin' Down a Dream." The four-disc collection comprises a double-DVD documentary, a DVD of the band's 30th anniversary concert in Gainesville, FL, and a soundtrack CD featuring rare and unreleased tracks. A companion coffee table book is also available.