As noted at Maggie's Notebook:
Speculation is running wild, including the suggestion that he could be considered for SCOTUS (!). If you wiegh the fact that Stern has not only enjoyed unprecedented WH access for a union thug like himself, but is already a force to be dealt with within the leftist cabal that runs this country, nothing should surprise us, really- especially with Obama getting more obstinate and radical by the day.
But Michelle Malkin observes that it may have had to do with internal union politics as anything else- as perhaps the new AFL-CIO leader Richard Trumka wishes to re-assert influence over an SIEU that grew more independent under Andy Stern. And Trumka pushing Stern towards the door is nothing to get too enthused about, as he's the one who was caught lying last week about hearing racists taunts from TEA Party activists.