With reports of Spider-Man 4 may miss its May 6, 2011 release date, rival studios are wasting no time taking advantage of the situation. Paramount Pictures has moved up the release of Thor from May 20, 2011 to May 6, 2011. Additionally, Walt Disney Pictures has settled on a May 20, 2011 release date for Pirates of the Caribbean: On Stranger Tides.
With two high profile films releasing within two weeks of each other, it’s highly unlikely that Sony will release Spider-Man 4 in the same month. As reported the other day, it’s probable the film may move to July. However, if the delay is more than just a short-term situation, it’s entirely possible that the film could slip to summer 2012.
Source: Box Office Mojo