People were afraid that it's much more dangerous.
And note that it's not just any "slight change" that works. Shrinking it by 30% did not, for example.
Perhaps, just to differentiate, for the next iteration they could go with a sea urchin inspired design and put spikes all over the back. I'm sure that would make a great tablet. Or they could use a design that makes sense, and risk getting sued again.
If changing the size dramatically, using a different aspect ratio, and having different styling isn't enough, what is?
Edit below: clarifying that the whole product is the consideration. Also, they all look like a blackberry a few miles away; the point is what do they look like to the user.
So you'd have trouble distinguishing among the Microsoft Surface Tablet, the Kindle Fire, and the iPad? How about when they are on?
http://geekntech.com/wp-content/uploads/2012/06/Surface-tabl...
http://www.blogcdn.com/www.engadget.com/media/2011/08/galaxy...
http://www.eweek.com/images/stories/slideshows/ipad_security...
http://static4.businessinsider.com/image/4ec2a063eab8eae47e0...
Ok, I'm not entirely serious with that. The thing is that the keyboard is an accessory for the surface, and the styling of all the tablets is quite similar. (I was actually surprised by how similar when I looked up the images). If shipping an accessory is enough to prevent design patent infringement...
I still think that design patents should not exist. If there really has to be a design patent, then it should be very specific and not like the one for iPad.