Nit: It's 16:10, but I agree that 4:3 is a great aspect ratio for tablets, especially if it is being used for reading. I really wish there were more 4:3 tablets around.
I really like the 4:3 ratio on my 8 inch Vizio tablet; so much so that I've been avoiding upgrading to Honeycomb. Android 3's onscreen toolbar would definitely throw off the usable aspect ratio.
