A Holy Grail of gamer memorabilia is the Portal turret replica -- as much a tech toy as proof that you can sing "Want You Gone" from memory. It's already been coveted when made in small batches by fans, so you can imagine the hysteria when Valve Software itself posts a teaser video (found after the break) at its store's Facebook page showing what looks to be a near life-size, computer-linked version of Aperture Science's typical sentry from Portal 2, minus the laser targeti
