Lastly will be the precision Lego 3D printer in which one may print Lego compatible parts including the Lego 3D printer.
oh, i am soo waiting for that. you can already print compatible bricks now, but the results are not quite there yet, but that's totally the future. instead of buying sets in a shop i'd lofe to just print out the parts at home. one nice thing is that, since the parts are so small, it's much easier to deal with print failures, because reprinting a broken part is much easier than reprinting a whole model.
They'd only need create a few 'scientific' bricks to make them work. Not that different from Mindstorms.