Microsoft lost me the moment they mentioned "the tablet you already own" when I don't even own a smart phone. If I own a 360, I would need a phone or even tablet to take advantage of SmartGlass games. If I own a WiiU, I can take advantage of any and all games using the WiiU Game Pad... unless they used two I guess.
Still, this does mean that technically all three systems can somewhat manage WiiU GamePad style technology. I wonder how risky that is? As has been said, some companies or people, especially the smart phone gamer types, might lean towards the 360, ignoring the buttons and thinking "it can do the same thing" for example.