https://www.crowdsupply.com/mnt/reform MNT Reform is a step in that direction (+ open hardware!) The CPU and RAM are on an easily replaced SO-DIMM, so you could have a variety of system configurations use the same laptop-peripheral-complex.

My hope is that something to that effect comes about with the growing use of SO-DIMM-like form factors for SBCs (e.g. RPi Compute Module, SOPINE, etc.). Unfortunately nobody seems to be cooperating on a standard pinout yet, but if we can get to the point where they're interchangeable that'd be a boon for all sorts of things (be it popping a module or two into a laptop or popping dozens of 'em into a server).