The dilemma for the Pope is that the situation has forced him to choose between his hatred of all the sex-abuse filth in the Church and his love for vibrant, orthodox "ecclesial movements" that produce priests. Leave Maciel alone for the latter's sake, and the papacy ends up doing nothing about what at least appears to be an egregious instance of filth at a high level. Punish Maciel, and the papacy might demoralize a loyal movement that has aided the Church greatly in recent decades. But in the end, the cumulative allegations seem to have borne enough credibility to make some sort of meaningful action imperative. And so it has come about.
Here we have one of the most important signs that Benedict puts principle over politics, even Church politics, when the two conflict. Given the ever-louder chorus for him to approve condom use for married couples in which one party is infected with AIDS, he will need all the courage that such integrity can provide.