Padfone, sounds better that Atrix
I think that the Padfone concept (if correctly executed) should be a huge win. There is a much greater overlap in use between smartphones and tablets with a real blurring of the boundaries and this concept will give you the opportunity to simply choose the best form factor depending on where you are.
The Atrix seems to promise somehtig siilar but the second form fator there seems to just be a gimped netbook that offers little more than a Firefox browser. I can buy a smartphone and a netbook, (that runs more than just Firefox), for a lot less then the Atrix combo - so I don't see the point.
The Padfone seems to be a much more unified proposition.
I like the idea of effectively using one procesing engnie, one 3G connection, having one place to store key files. One ring to rule them all?