It's true that Blair House is booked on dates prior to January 15. But it's not true that this is some kind of "snub" or "diss" of Obama. Obama wanted to move into Blair House early. But Bush had previously booked it for a former head of State (the truly awful former Prime Minister of Australia, John Howard). As a result, Obama can't move in early, but will move in on the standard date.
This is a scheduling conflict. Calling it a "snub," and hyperventilating about it, is frankly embarrassing and reminds me of the outrageous accusations leveled by Republicans against the incoming Clinton Administration back in 2000 (they removed all the "W" keys!). It also mirrors classic "village" behavior where everything is viewed through the lens of cat-fighting amongst the cool kids. Sometimes a cigar is just a cigar and sometimes a scheduling conflict is just a scheduling conflict.
We have very very important matters at hand, and we can't afford to be distracted. Let's move on.