Where'd everything go?

There seem to be a LOT of sudden retail vacancies this month. Central Square lost Pearl Art and the Attic. Downtown Crossing, which was pretty vacant to begin with, lost a whole block of stores on Winter Street - whatever building Staples (soon CVS) is in.

We've had lots of closings over the past few years as the recession hit, but I don't remember so many places disappearing at once. Any theories? Post-holiday slump?