The Sony S1 comes with a 9.4-inch screen and a unique "off-center of gravity" form. It's heavier on top, so it's easier to hold for longer periods of time, and the soft keyboard has been optimized for the larger screen. No word on if there's any cameras included with this model, but I can't imagine there wouldn't be.
Looking a lot like a cross between the Kyocera Echo and a Sony Bloggie, the S2 comes with two 5.5-inch screens that can be used together to surf the Internet (though a big crease in the middle of your webpage might get annoying), or separately to draft emails, text, or watch movies. The S2 folds up nicely, so it should fit into the smallest of bags and could be handy for travel.
Get a different look at both tablets in a demo video from Sony, and tell me what you think of these offerings after the break.