Great question; just since we made the video, a lot has happened in La Puerta del Sol. In fact, the door and tent structure in the photos of Sergio and Spicy Tutuboy, built as part of the protests, were wiped away by the Spanish government last week during an unprecedented 3 day shutdown of the Puerta del Sol metro and train hub.
You can read more about the recent shutdown in English:
or in Spanish:
Also, here's a great short summary of the movement on the eve of the elections in mid-May:
In English you can also just google “protests Sol Madrid”; in Spanish you can find out more by searching for movimiento 15-M (named for the first protest in May), or los indignados (the indignant).
I’d be delighted to post more news stories about the protests if there’s interest; comment here if you want ‘em.