Obama sells out?

It's everywhere in the blogosphere today, but it's nowhere in the press that i've seen. It's the bubbling sponsor-gate the world witnessed as Barack Obama gave his mini-concession speech after yesterday's loss to Hillary in the PA primary. Is it paid endorsement? is it Guerilla marketing? is it whack coincidence? The blogosphere is divided. What do you think? 

I will point out that none of the t-shirts in question had a URL on them. i'm imagining a "secret" url tied to some underground group either in support of or against obama. that would have been interesting to behold. And to ponder.