Usually, when a big video game gets delayed, you can easily call out the reasons: development wasn't proceeding as planned, more time to make it even better or porting it to other platforms.
But, in the case of toy/video game hybrid Disney Infinity, the release month is shifting from June to August because retailers asked. A New York Times article quotes Disney Interactive co-president John Pleasants:
Mr. Pleasants said retailers, impressed with the public reaction to Disney's demonstration of Infinity in January, pushed for an introduction closer to the all-important holiday season, which starts in October. "The date became an issue in terms of them asking, ‘Is there a better opportunity here?' " Mr. Pleasants said.
Pleasants' remarks in the NYT piece also make it seem like Infinity is on track to be done in June. It's an odd change of pace for retailers to want a game to come out later in the year, but the thinking seems to be that this will give the cross-platform title a clear runway to impressive sales. The new timeframe also nudges Disney Infinity closer to the late 2013 debut of Skylanders Swap Force, the upcoming entry in Activision's super-successful collectible-toy-game franchise . Guess we're going to something closer to an actual showdown between the two plastic kingdoms when they both hit store shelves later this year.
Disney Delays Release of Video Game and Toy Initiative [New York Times]