As the Nokia Lumia 800 has shown, there is still a lot of room for design in smartphones that don't resemble the iPhone as well. Samsung has no excuse.
Go and take a look at the flat-screen TV section of any electronics store. All of them look pretty much alike, and actually also very much like iPad. The main difference is size, and iPad's rounded corners which are nicer to have in a device that you hold in your hands.
You can even compare Nokia's circa 2005 Internet Tablet, the 770 with an iPad. Same black color, bottom corners are rounded. Sure, it still has some more buttons and a resistive screen, but it even came with a "smart cover" (turn the hard cover around, and the magnets in it will put the device to sleep) http://www.flickr.com/photos/bergie/4554791832/
On the general topic, I remember being interested in tablets early on when they were a Microsoft thing and none of them looked like an iPad. Now almost all tablets look iPad like. Samsung in particular seemed to have gone out of their way to make a product that mimicked the look of an iPad. That being said, I'm sad that Apple has taken to the courts over these small issues. The best way to have a leading product is to make a leading product and then continually improving it so that customers want to buy it. This Apple does well. But as an Apple shareholder I'd say playing defence with court suits is a waste of $£ in my opinion but sadly Apple execs didn't ask me. On the other hand withdrawing the bulk of $8billion in parts purchasing from Samsung should have made the point alone IMO.
In fact, Samsung makes TVs with red frames, which they brag is a feature:
http://ars.samsung.com/customer/usa/jsp/faqs/faqs_view_us.js... http://www.pause.com/wp-content/gallery/08-07-23-samsung/08-...
So designers at Samsung are perfectly aware you can make the bezel other colors.
Given that Apple itself has tablets shipping in white, I'd agree with this.
This article does a good job of presenting how Apple potentially came to the answer of how a tablet should look, but as noted above, that doesn't necessarily mean that it's the be-all and end-all of tablet design. It just means that Apple tablets sell well enough to "force" everyone else into their vantage point.