Jin Soo Kim, a Samsung industrial designer, was called to the stand today by Samsung at Apple and Samsung's court battle and revealed this: the Galaxy Tab 10.1 project couldn't have ripped off the iPad because the Tab 10.1 project began in October 2009 (while the iPad was announced on January 27, 2010). Kim even went as far to show off an e-mail dated three weeks before the iPad's announcement that included a design very close to the Tab 10.1.
The Verge reports that Kim said each aspect of the tablet was designed with usability or efficiency in mind (not because they were cribbing from the iPad). As for the claims that Samsung redesigned the Tab 10.1 after it saw the iPad 2's thinness, Kim says that Samsung had long been trying to make a thinner Tab 10.1 after seeing the tablets at Mobile World Congress in 2011.
AllThingsD reports that Kim said Samsung wanted to make the lightest and thinnest tablet in the world to a gain "a competitive advantage" over the faceless lineup of tablet devices, not because it was specifically targeting Apple.