If ported to ARM it could become quite a thing in embedded development. I'm not thinking about the latest Macs (although... why not?) but rather very small and cheap embedded boards where Linux could be either too resource hungry or overkill. On these small boards a very light GUI oriented OS like SerenityOS and a set of gfx libraries and primitives could be the right tools to make appliance control panels, instrumentation, etc, and of course general computing.