The manufacturers are copying the iPad design because the iPad is popular and because they don't have a single other bullet point to compete against it. "Android" isn't a marketable advantage for 99% of the population. So along with the iPod physical design, they make mods to Android to offer something more than other Android handsets, and at the same time to give some iPad looks (for some of these guys anyway).

I haven't seen anything to indicate that Android is any good on a tablet device without mods. What kind of native support does Android have for these larger and higher density screens? Have any apps made use of any such features? Is there any style guide for creating apps for a larger screen? What happens to older apps when used on these displays?

So far I believe Apple has the tablet game sewn up tight. Much more so than they have ever had (or ever will have) with the phone market.