24 Days of LEGO Christmas is the name of this LEGO model. It was created by brick_a_brad and this whole building is one giant advent calendar. You can look at future "days" now, by zooming in on the rooms in the linked main version of this picture (link: flickr brickabrad lightbox, or you can see the rooms revealed day-by-day at their web page here: http://www.flickr.com/photos/brickabrad/sets/72157625352594180/
It was found through one of my favourite sites - http://lmotd.blogspot.com/ (Fascinating LEGO Model of the Day): "This was part of an even larger project for a few toy store windows, and you can see some behind-the-scenes photos and photos of the other parts of the displays in this photo set. You can see much of this model already, and there are also some bits in LEGO Digital Designer showing the design process for this model and the ski lift scene."