There are speculations that Apple will launch iPad 3 in September .
iOS 5 for developers was released in WWDC 2011.
9to5Mac reports that graphics of iOS 5 SDK reveals that iPad 3 will sport Retina Display having a resolution of 2048 x 1536.
The resolution of iPad 2 is 1024 x 768.
A set of graphics found in the Twitter.framework of the iOS 5.0 SDK reveals 2048 × 1536 display.iOS 5 SDK has support for the iPad 3 hence it is likely that iPad 3 graphics will b epresent in iOS 5 SDK and Twitter framework is present only in iOS 5.
TechUnwrapped have found that iOS 5 iPad Newsstand application also shows 2x images which was also found in iBooks earlier this year which supports that iPad 3 will have Retina Display.
According to 9to5:
Due the circumstances in which these new iPad 2X graphics were found, we feel that these icons are not just a coincidence or a designer thinking ahead, but rather a strong indication that the next iPad will feature a 2048 x 1536 Retina Display.
Will update you more on iPad 3 and iOS 5.iOS 5 will be released by fall this year.