The idea is that computers will become more and more ubiquitous. As folks upgrade, they will have more and more cast-off PCs/Laptops. For most people (non video/game enthusiasts), the minimum system requirements are not very high- meaning that all of those old systems can fulfill their needs. BUT, the time it takes to maintain each old computer will keep people from using them. The solution is that each person maintains their personal operating environment then carry it from computer to computer as necessary. All the computer needs to do is boot from USB (which is becoming more and more common)
Forget this specialized laptop idea- polish up a good general-purpose hardware-sensing environment that survives on USB flash drives and market that instead.