Assembly shouldn't be required (could be pre-configured from factory) but I don't see any reason why the top deck of a laptop couldn't be modular so the same model could support a more MacBook-like config with a centered keyboard + trackpad with no numpad and larger speakers OR an off-center keyboard and trackpad with numpad and smaller speakers.
Actually, thinking about it, it strikes me as slightly absurd that this isn't an option on at least a few mainstream laptops.
