I thought it would be great to have one device as well, but then I realized that sometimes I want to use my phone while watching TV or using the laptop, so they can't really be one device, unless I wear a wireless headset, which I don't really want to carry around along with my phone (another thing to charge, another thing to lose).
A multi tasking OS with a powerful CPU and wireless video streaming should provide those at least in theory. There is actually Miracast http://en.wikipedia.org/wiki/Miracast so in theory the bits and pieces are here already they just have to work as a package.
