Looks more like some after-effects edit than projections to me.

At 2:12, on the top-left part of the building, the water effect is "leaking" outside the actual surface of the building towers and lighting up some of the open air there.

At 2:18 the water effect at the bottom-left is covering the heads of two people walking there, without creating any noticeable black shadows on the building.

Also, I would love to see the projector that could create such a fantastically accurate and HD image on a building that size, consistently, without any effect from local lighting, and from that kind of distance.

What's the song?

There's another video showing a "live" performance which looks more convincing
http://vimeo.com/5677879

Music is The Asteroids Galaxy Tour - "Around The Bend".

Also some similar stuff in the showreel at http://www.easyweb.fr/

Great points Demon. I was thinking the same thing while I was watching.. but still - wow.

And, to add to Demon's litany, not a single person is watching the show. If I saw such a display as I was riding my bike by I'd stop, or at least GLANCE at it!

And part 2, no projector can compensate for the variation in colouration of the screen the way it would have to for this to be real, black parts of the building would be darker and white parts lighter, shiny surfaces would interact with the lights differently from dull ones.