People seem to believe that a video uploaded five days ago with the title "Wybuch w Oslo – Explosion in Oslo – 22.07.2011" predicted the explosion. However, Google reveals that the original title was actually "SZOKUJACY FILM nawałnica burza nad Polską 20.07.2011".
Here is a screenshot showing the original title, as cached by Google:
Click the image to see more of the search result page.
The evidence clearly seems to show that it is fake.