I Know Samsung (n1 in smartphone market by size) has DEX [1]. It does what you want (theoretically)
you can alternatively combine the Tablet + Desktop part with something like a Windows surface pro.
Instead of this kind of uber-minimalism (what about the smart TV, the i-watch, the ereader...), I will rather reason in term of quality/longevity and repairability/modularity. Apple is only good at the first.