There's lots of speculation in the Opposition and elsewhere (queue link to the charming, Canadian Cynic) that Steve has prorogued Parliament to avoid questions about Afghan detainees.
This time, I think Steve is actually telling the truth - it's not about covering up allegations of torture. He's quite happy to leave Defense Minister, Peter McKay, flapping in the breeze trying to deny or hide any knowledge of detainees being tortured. There's no love lost between the two men, in fact many have speculated that Harper gave McKay this portfolio to doom his political career. Steve would not shed any tears if McKay is forced to resign. (Could Steve ever shed tears? A question for another day...)
I suspect the real reason Parliament has been prorogued is to hide the fact that the federal finances are in far worse shape than Steve and his pal, Finance Minister Jim Flaherty, would have us believe. Keep your eyes open for a report from Parliamentary Budget Officer Kevin Page next week. He may be our only link to the truth about our financial situation in these undemocratic times.