I think artists should stfu about politics, unless it's a political show. Political statements get used so often that they no longer ring true. "Bush Sucks" is just another way to rake in that hippie ticket money. They're at Bonaroo. Talk about how much weed they're going to smoke; it's about as effective.
I tend to agree, but seriously, what the hell were they expecting from Pearl Jam? They've been very vocally anti-Bush since he was first elected, and their music has been political all the way back to Ten.