

Though the site doesnt specify, the above image may be of prototype case for the iPad 3.According to Asian supplier which provides part for next iPad, next iPad has same size of screen, but case may be thicker by unknown reason. Current iPad cases, which covers backside, will not be compatible with thicker next iPad.
Also the source told, front rounding corner will be same with current iPad, then Smart Cover will be good companion with new iPad.
Mac Otakara has occasionally offered accurate information in the past, although several of its claims also failed to come true. Back in August, the site claimed that the iPhone 4S and iPad 3 would debut at a media event in early October with availability set for late October. iPad 3 rumors had been swirling at the time, but were later discounted as reported indicated that Apple will be pushing the iPad 3 with Retina display back to an early 2012 introduction.
Article Link: iPad 3 Will Be Thicker, Still Support Smart Cover?